Hardware
You need plenty of hands-on time with this camera before you take the plunge, and you need to be clear on what type of applications you want it for.
Unboxing could be a full-on culture shock for the uninitiated. The X-Pro1 is designed to appeal to rangefinder lovers who dig over-sized control wheels along with over-sized everything. That's not everyone's tipple: we gave the camera to a seasoned photojournalist freshly returned from the Middle East who normally shoots on a Nikon D3, and she was repulsed. In her mind, it was too big to be a compact, too conspicuous, and too retro for her: "I'd be embarrassed if other photographers saw me with this."
That said, it's all subjective. Yours truly also has a foreign news background, though I've generally shot video rather than stills, and I experienced no such allergic reaction. On the contrary, the X-Pro1 brought back memories of when my first employer sent me off with a celluloid Nikon F3 to "go and learn about lenses." Yes, I was surprised by the size: at 140mm (5.5 inches), the body is significantly wider than the new Olympus OM-D Micro Four Thirds camera and 20 percent wider than even the non-ILC Canon G1 X.

No one could dispute that the X-Pro1 is solidly built and surprisingly lightweight for its size -- around 650 grams (1.4 pounds) with the 35mm lens attached, and easily usable with one hand. However, despite all its volume and mass, this camera is not weather-sealed, which will put some serious photographers off from the get-go.
The moral of the story? You need plenty of hands-on time with this camera before you take the plunge, and you need to be clear on what type of (hopefully dry) applications you want it for. Oh, and don't feel obliged to splash extra on the LC-Xpro1 leather case if you already use a camera bag -- it isn't strictly necessary considering the natural sturdiness of the chassis, and it perhaps pushes the retro thing a tad too far. On the flip side, it'd go great with safari shorts.

One of the biggest contributors to the X-Pro1's size (and no doubt its price) also happens to be one of its most useful specs: the hybrid viewfinder.
One of the biggest contributors to the X-Pro1's size (and no doubt its price) also happens to be one of its most useful specs: the hybrid viewfinder, which has been carried over from the X100. It simply caters for any possible situation, by allowing you to switch between optical and electronic modes. Optical gives you the brightest and most direct view of your subject because you're looking at them straight through a piece of glass. Electronic mode, which has an 800 x 600 resolution (or 1.4 million dots), gives you the most precise preview of your final image, with framing and focus displayed before you press the shutter. Both modes can be overlaid with all the information you need, including a live histogram, spirit level and lens-matched frame guides optical mode. Helpfully, the OVF also changes its magnification automatically when you switch lenses, so you get a broadly more similar view to what your lens sees. Overall it's not quite as natural as a DSLR's reflex system, but it's as good as you'll get on a compact.
Of course, there's also full viewing through the three-inch LCD panel, with an effective resolution of 640 x 480, which we found to be bright and clear when shooting outdoors. It's even usable in direct (albeit British) sunlight, which we guess is at least partly thanks to the RGBW configuration.

Before we get to the controls, a quick word on the lenses: there's already a Leica adapter in case you just happen to have some Leica lenses lying around, and a few others out of Hong Kong, but for now the camera is natively stuck with the three prime lenses for its all-new mount. These are truly delicious: an 18mm f/2.0 lens for your wides, a 35mm f/1.4 beauty for general use and a 60mm f/2.4 for zooms, portraits and macro photography. All these lenses come with quality metal hoods.
What we'd really like is a nice, fast and quiet zoom lens to go with this camera and it's all-new mount, and Fuji assures us that such a thing is in the works. Working with the currently available lenses will reduce your hit-rate if you're not already used to 'thinking' in terms of primes and planning ahead so that you have the right glass equipped for the shot you want to grab. For someone who's been raised on a lazy diet of powerful zooms, this is bloody difficult, but it can hardly be blamed on the X-Pro1. Over time, the discipline required to shoot with primes can only be healthy to learn.
User Interface

Now, those controls: they're perfect, or at least almost perfect. There's no ISO dial, but we're beginning to realize that Engadget staff may be more concerned about that than the average photographer, because we're forced to take so many close-up shots of gadgets in low-light situations. What we get instead is three other dials that all make a ton of sense for most situations, plus the aperture ring on the lens itself.
The shutter speed dial works exactly like you'd expect, except it has a slightly superfluous lock button to stop you accidentally shifting it out of Auto. To its immediate right sits the exposure compensation dial, which feels like a more natural part of the workflow as result of not being a two-stage setting like on many other compacts and DSLRs. The dial is too easy to knock accidentally, but only until you learn to be a bit careful.

At the back of the camera is a mystery dial that at first seems to be useless -- especially when you make a habit of never reading the manual. But when you discover what it does, there's a genuine "Oh, right!" kind of moment. This dial works hand-in-hand with the Q button, which brings up a quick settings screen. This screen is comprehensive rather than customizable: every likely adjustment is offered; you use the direction buttons to navigate the grid and select the one you want to change; finally you twiddle the anonymous dial to choose the right setting. You don't have to accept your changes, which means that all these settings are brought within a three-step reach. Three separate actions just to change ISO or white balance might sound like a lot, but the point is that you can access them without taking your eye away from the viewfinder (because the Q screen appears as an EVF overlay as well as on the rear panel) it works a treat.
In addition to Q, there's also an assignable Fn button next to the shutter release. You can stick ISO or any other function on this button instead if you prefer, but it won't really speed things up: it's still a three-stage process to hit Fn, select ISO with the arrow keys and then hit Menu / OK to accept. Other functions will have less steps and therefore make more sense, such as depth of field preview.
Battery life and performance

It needs to be said that the X-Pro1 with the prime lenses doesn't auto-focus as fast as a regular DSLR kit, especially in low light, and the focusing is noisier too. You could spend $1,000 on a Nikon D5100 and a fast lens and get better AF performance, including the ability to get macro shots without having to tell the camera first. There's something slightly icky about that thought, and it's a reminder that our skeptical photojournalist friend might have a point -- in fact, the slow autofocus was also one of her biggest criticisms. It's so bad the continuous focus mode seems almost redundant -- we couldn't use it to track anything, even the object was right in the center of the frame. The shot above was taken with continuous focus, and neither the guy nor the houses are sharp.
Shooting from a standing start was less rapid -- it took around five seconds to power up, focus through the EVF and snap a shot. Using the OVF or rear LCD reduced that to four seconds. This is all way slower than the Sony NEX-7, for example.

Meanwhile, the Drive performance was great. Shooting RAW+Fine duplicates at the 6fps drive mode setting, we fired off 11 shots in 1.8 seconds before the buffer filled up, which is just under 0.2 seconds between each shot. Shooting Fine JPEGs we could keep going, achieving 37 images in the space of 11 seconds, with slightly inconsistent gaps between each shot, ranging from 0.1 to 0.4 seconds.

Another positive is the battery life: we repeatedly lost track of it, for the simple reason that it lasted so long. As these words are being written, the camera has been used on five separate occasions over four days without being recharged, with 680 Fine JPEGs, 100 RAW images and four minutes of 1080p video captured. The battery still shows two out of three bars. It took another 11 minutes of 1080p to finish it off.
The X-Pro1 does crash occasionally -- three times for us so far. We simply loosened the battery to restart the camera, and it wasn't so annoying because we tended to be previewing images when it happened. Hopefully it's something future firmware updates will fix; Fujifilm has a decent track record in that respect.
Image and video quality

Ah yes, the magic ingredient: the X-Pro1's bespoke Fuji X-Trans CMOS sensor. It's the right size for the resolution: anything smaller than APS-C would make the 16 megapixels too crowded, while anything bigger would make focusing even harder. More importantly, though, it delivers surprising results: images you just could not predict and that you almost don't deserve. If you've ever taken a shot on celluloid, processed it and then thought "Wow, did I shoot that?" then you'll know what we're on about. If photography were an Olympic sport, this sensor would be the equivalent of nandrolone.