With 'Deep Learning' autofocus, crazy-fast burst speeds and refined ergonomics, the Olympus E-M1X is the most focused action and sports shooting camera that Olympus has ever made. And though it retains a Four Thirds sensor like the E-M1 II, Olympus is touting the X as a credible alternative to the flagship Nikon D5's and Canon EOS-1D X II's of the world: in the right circumstances.
We'll look at comparisons against the D5 and 1D X II in a future article, but for now, we wanted to take a closer look at how the E-M1X stacks up against other Four Thirds and APS-C cameras with sports-shooting chops. It's true that the E-M1X is the only camera in this comparison with a true double-grip chassis, but its competition is fierce nonetheless.
Against the E-M1 Mark II

Olympus has been clear that the E-M1X does not replace the existing E-M1 II, and both will live alongside each other in their lineup. But since the E-M1 II was already such a capable camera and you can get one at a steep discount compared to the X, we figured we'd start with a look at how these two stack up against each other.
The most immediate change is obviously the body. Not only in terms of size, but also battery life (doubled on the X, since it has...double the batteries). There are also significant differences between the two in terms of their controls. By and large, there are more buttons on the X that are dedicated to a single purpose, and the dual 8-way joysticks free up the four-way controller to act as four distinct custom buttons.
Against the E-M1 Mark II

Another benefit of the larger body on the E-M1X is that it makes room for an all new in-body image stabilizer, now rated at up to 7 stops without a stabilized lens, and up to 7.5 stops with certain lenses such as the Olympus 12-100mm F4 Pro. The E-M1X is also officially rated to IPX1 standards, something shared with the E-M1 II but not with any other cameras in this comparison.
Both cameras have the same viewfinders, the same rear screens and the same
(or very similar) sensors
Olympus also doubled the processors in the X relative to the Mark II, enabling not only the 'Deep Learning' autofocus that detects motorsport vehicles, aircraft and trains, but also the hand-held high-resolution mode that spits out 50MB files. And Olympus has told us that it's tweaked its C-AF algorithm in the X (note, this is not the C-AF + Tracking algorithm) to allow for better autofocus performance when you keep an AF area over your subject.
As for the rest, well, there's not much to tell. Both cameras have the same viewfinders, same screens and the same (or very similar) sensors and very similar menu systems. For all intents and purposes, unless you need a tougher camera, want a beefier camera to use with bigger lenses or are in love with the Olympus ecosystem and want the best possible autofocus performance your bucks can buy, it's probably best to just stick with the E-M1 II for now.
Against the Panasonic Lumix DC-G9

Let's start with Panasonic's Four Thirds stills-shooting flagship, the G9. Although at first glance there doesn't appear to be much between the two in terms of core specs, the experiences of actually using each of them are more disparate than you might expect.
But let's start with those specs, just 'cause. While the E-M1X shoots at 18fps with autofocus, the G9 ups the ante with 20fps. But they both have 20MP Four Thirds sensors with native ISO ranges of 200-25600, they both have fully articulating rear touchscreens, AF joysticks and in-body image stabilization.
But whereas the E-M1X has an on-sensor phase detection autofocus system that is able to recognize subjects like aircraft, trains and automobiles, Panasonic has stuck with its Depth from Defocus technology in the G9's contrast-detection autofocus system. The result is that there is 'flutter' in the G9's EVF when shooting moving subjects, as the lens rapidly wobbles in and out of focus to reconfirm critical focus. The 'keeper rate' of in-focus shots on the G9 is actually quite good, but it can be difficult to see while shooting if your subject is in focus at all. It's a bit disconcerting until you get used to it.
Against the Panasonic Lumix DC-G9

There are other considerations, such as the G9's top-plate LCD that displays shooting settings, something missing on the Olympus. Both cameras have high-resolution modes, but only the Olympus lets you hand-hold the E-M1X to get those extra pixels. The G9' s video spec is rather more impressive too. It shoots 4K/60p, while the Olympus tops out at 4K/30p. Missing a built-in battery grip, the Panasonic is of course smaller, and with around half the rated battery life of the Olympus.
Both cameras give great results from their Four Thirds sensors given enough light. In the end, we lean towards the Olympus for outright autofocus performance, but the Panasonic is the stronger option for those who also dabble in video.
Against the Nikon D500

Okay, with the E-M1X's main Four Thirds competitor out of the way, let's look at how it stacks up against Nikon's APS-C flagship, the D500.
With a resolution of 21MP, the D500 is only slightly above the E-M1X in this regard - but the larger sensor will come with less noise, more dynamic range and better low light performance than the E-M1X. Physics is physics, simple as that.
The larger sensor in the D500 will have less noise, more dynamic range, and better low light performance
And while the D500 comes without any form of 'Deep Learning' in its autofocus system, it does have a highly capable 3D Tracking mode to track moving subjects. So it won't automatically detect, say, a car, but if you manually tell the camera what to track, the D500 will stick to it with remarkable tenacity. By contrast, Olympus' non-subject specific tracking is nowhere near as 'sticky' as the Nikon.
Against the Nikon D500

The viewfinder experience differs from one camera to the next, and not just because one is optical (Nikon) and one is electronic (Olympus). The Olympus' viewfinder is noticeably larger than that on the D500, but because it uses LCD technology, contrast is lacking and blacks can appear somewhat 'washed out.'
The D500 also tops out at 10fps, slower than the E-M1X but still respectable. Despite only having a single battery, the D500 is rated for more shots per charge than the E-M1X, in part because it doesn't have to power its viewfinder. But the Olympus has incredible image stabilization, and Nikon's lens lineup offers limited solutions for getting near the reach of the Olympus lineup without spending more money and carrying more weight.
In the end, both cameras will reward you with an insane number of in-focus 'keepers' and good image quality - but the Nikon will handily beat the Olympus as light levels drop and ISO values rise, while Olympus gives you more reach in a smaller overall package.
Against the Fujifilm X-T3

Aha! You weren't expecting Fujifilm to make an appearance, were you? But the X-T3 is a credible contender, offering further evidence that Fujifilm is quickly learning from both its past and its competitors. It wasn't that long ago that Fujifilm offered dismal video and slow autofocus, yet now the X-T3 is a stills / video hybrid camera that is among the best APS-C cameras we've ever used. So how does the E-M1X look against it?
The X-T3 has the highest resolution of any camera in this slideshow
With a new sensor offering 26 megapixels of resolution, the X-T3 will have the highest resolution of any camera in this slideshow. It also reads out very fast, allowing for 20fps burst shooting using the electronic shutter, and 30fps with an added 1.25x crop that yields 16MP images.
But what good are burst speeds if your subject is out of focus? Good thing the latest autofocus system in the X-T3 is really good, with a solidly capable tracking mode that works similarly to Nikon's 3D Tracking. Also like the Olympus, there's no top-plate LCD to check your settings, but that may not matter if you make use of the analog dials. And one last small-but-significant distinction: the E-M1X has a large AF-L / AE-L button that can be assigned to AF-ON for back-button shooters, and the X-T3's AF-L and AE-L buttons are comparatively small and placed less conveniently.
Against the Fujifilm X-T3

Despite its relatively large sensor, the X-T3 will also be the smallest camera in this comparison - but that portability comes with compromises. The Fujifilm's smaller grip is less well-suited to large lenses than the Olympus, and battery life is comparatively poor. But build quality is excellent, even if Fujifilm won't commit to an ingress protection rating like Olympus will. Despite having excellent video capabilities, the Fujifilm has no in-body stabilization, limiting video shooting possibilities for some users, though it has a much nicer electronic viewfinder and zero-blackout shooting in those electronic bursts.
Like Panasonic's G9, the Fujifilm X-T3 may be best seen as a more appropriate all-rounder for most people. But Olympus should be concerned about the little Fujifilm, particularly as the system has some excellent lens support that signals how seriously the company is taking sports and action shooting (see the XF 100-400mm zoom and the 200mm F2 prime). Fuji also offers - arguably - some of the best JPEG color in the business, which is not only an Olympus strong suit but also very important to action shooters that don't have time to process thousands of Raw files.
The wrap

In looking at the E-M1X in comparison to these excellent crop-sensor cameras on the market today, you can't help but wonder if Olympus really has their work cut out for them.
It occupies an interesting niche in the market. Olympus is clearly catering to users that may either aspire to own a professional double-grip DSLR, or perhaps already own an SLR of some sort but are tired of carrying it around. These users must be shooting in pretty decent light to avoid ultra high ISO values compromising image quality on the Four Thirds sensor and yet, these users must not want to compromise at all on autofocus capability.
There's no denying that the E-M1X is an amazing piece of technology wrapped in what is perhaps the best-built camera body any of us have laid our hands on. In the right hands and in the right circumstances, it's capable of astounding imagery. We'll continue to put the camera through its paces as we press on with our final review.
What do you think of the E-M1X? Do you own any of the other cameras mentioned in this comparison? Do you want to pick up a copy of the Olympus for your very own? Let us know in the comments.