I'm not "planning" to get the L mount, but I figure I just might, eventually, depending on price. I like the idea of the FF sensor size and 20MP per layer. The image results, both color and detail "resolution" should be excellent. Micro-contrast should be superb.
My point of view, however, is something like this:
My sdQ is a very well made and implemented "quattro architecture" camera with excellent detail resolution and great color. I usually do not print beyond medium-sized final prints, and I generally use the whole image frame. Most of the time I make 8x10 prints. I like the BW images from the sdQ.
So: As it is now I don't come close to what the sdQ camera can do.
Similarly, as I see it, unless "post-processing" is done with some real care and skill, the difference between a good sdQ image and a good 20MP FF image is not going to be that great.
I do not generally take pictures of clouds.
And honestly, if I want a MF image or, if I may be so bold, if anyone does, the best plan is to buy and use a MF camera and be done. MF just has a different (and I think better) look and feel than even FF.
I think for someone who had a 22 MP medium format camera, back when the Canon 16 MP full-frame 1Ds Mk II was all the range, and they were happy with that 22 MP camera, and they never felt a need for anything more, they might be quite happy with a full-frame camera today. The Nikon D850 and Canon 5Ds are really great camera - fast, lots of dynamic range, and very versatile cameras. They're also compact, in comparison to a medium format camera. The new Fuji will be a bit lighter and smaller than the Pentax 645 D/Z, but those lenses are still big, heavy, and expensive. I won't even mention Hasselblad. Certainly I could get a used Pentax 645 D. They're amazingly good value today, but they aren't what I want. In fact, I think my little SD Quattro H offers images with just as much detail. A Nikon D850 surely out-resolves the 39 MP sensor in the Pentax, being 45 MP, but maybe not. Surely the Nikon camera is much more usable, portable, and reliable. Maybe I'm wrong, but I doubt it. I work for a guy who has a 40 MP Hasselblad. He got the D850 to replace the D810, which he sold to me. Now he almost never uses the Hasselblad, and I'm sure that Hasselblad offers pretty much the exact same image quality as the Pentax 645 D.
The 100 MP Fuji will surely out-resolve my 25.5 MP SD Quattro H, the 20 MP full-frame Sigma, and any other 135 (35 mm) "full-frame" camera. This is why I'm considering getting one, if at some point I can afford it. I doubt I'll get it before I go sailing the Caribbean though. Maybe I'll come back, with the intent to get a bigger boat, and at that point it will most-likely make sense to go for a used 100 MP Fuji, with three or four lenses (probably costing well over $10,000). I guess I'll probably still end up taking an L-mount system, for portability, long-range shots of animals and what not, and for shooting video.