Obviously writing this thread in the Fuji forum was a mistake! I should have foreseen this. Yes, focal plane distance is shorter on Fuji, but that has nothing to do with it looking like a rangefinder and everything to do with it being a mirroless camera. The Oly's that look like SLRs are mirror less and have very shallow flange distance. Both use SLR like lenses, but neither is mechanically coupled to the body.This.The X-mount lenses are not "SLR" lenses, just like m43 lenses are not "SLR" lenses. The focal plane distance is different, allowing a shorter distance from lens face to the back of the camera.Remember: your lenses are SLR lenses.
There in lies the difference between these mirrorless rangefinder looking bodies which aren't really rangefinders. First there is no reason to put the eyepiece inconveniently in the middle of the screen so your nose smudges the screen and you have to smush it up against the camera to see, so they moved it to the side like a rangefinder. Second, since you don't need a prism box you can make the top of the camera flat, like a rangefinder. It leaves you a body that, coupled with a pancake lens, is much more compact and pocketable...like a rangefinder. One thing I miss, in all these rangefinderish cameras is the hand grip of an SLR. I wish they had just a bit more grip since even the flattest pancake lens sticks out a little bit so the grip wouldn't really make it wider.
The focal plane distance is the key feature that makes X-mount lenses different from SLR lenses, and very much like classic rangefinder lenses.
I look at the rangefinder-esque XP1 and X100 as the modern day rangefinder, but still very much a rangefinder. Think about your standard DSLR. With the exception of a few pro-models, they all come with a focus screen that's useless for MF and rely almost entirely on AF if you're looking through the viewfinder. These are the modern day version of our MF film SLR's and we don't look at them as any less of an SLR. Rangefinders on the other hand happened to be named after the focus mechanism used in the original MF versions of the cameras. If they were called anything else, the Fuji XP1 and X100 would without a doubt, be considered their direct descendants. The "rangefinder" part of the XP1/X100 has been replaced by an AF system just as the split screen of a DSLR was. The primary features of the camera remain the same. Your classic rangefinder and XP1/X100 have a viewfinder that allows you to see outside of your frame, a lens that sits very close to the focal plane, a viewfinder that sits off to the side, that compact box-ish shape, a quiet shutter and let's not forget having to deal with parallax errors.
As for "the X is just a fun wannabe that has none of the substance but all of the cheap flare." I guess this is true if you consider the mechanics of how you MF to be the most important part of your photography. For me, it's how you frame and compose your image. SLR's only see what's in your frame, my XP1/X100 sees much more than what's inside your frame-lines allowing one to compose within the viewfinder as well as anticipate what's coming into your frame. To me that's really the substance of a Rangefinder and the XP1/X100's have it. You don't get that from an SLR, and that's really "what's so special" about the rangefinder/rangefinder shape.
I was obviously too obtuse. I do NOT use Fuji lenses. A number of people who use the X cameras do not use X lenses. We use manual lenses. The X-Pro sort of has the build that we want. It sort of has the less ugly that we want. It has the manual ergonomic control layout that we want.
But its OVF is worthless. All it would take for Fuji to correct this would be to add a PIP overlay across the OVF, not the EVF. The camera could still be used like a rangefinder where we get the interaction with the rest of the frame.
In my original OP, you will notice that I use rangefinders and know about their plusses and minuses. What I don't get is why the Fuji crowd is so up in arms against anything but faux rangefinder styling. I love the styling of my X-Pro 1. Love it. But I'm one of those very cautious buyers. I won't buy into a new lens system. In ten years if it is still around I will consider it then. Until then I will continue to use my LTM/M lenses; where/when necessary I will use my Nikon F lenses.
There are a lot of people that use the EVF in the X-Pro because the OVF and frame lines are quite inaccurate (even compared to our old rangefinders), not to mention that precise focus isn't as possible as with a true rangefinder cameras.
I come down very very hard on all hardware I own. Fuji's biggest miss is their OVF. It is a great idea. But it is too small (next to a nice Voigt or Canon P); its EVF is too small and low res for manual focusing. Too much lag for focusing. Too choppy. That is all somewhat forgivable. What isn't is that the hybrid only overlays basic information. Why isn't it usable for manual focusing? Even white outline that would close in to focus when the lens was on target.
I appreciate your answer. I'm sort of answering to the thread, not to you.