frod

As usual, the best advice is to choose the lenses you require first and foremost. The system naturally follows from that choice.

Nikon are not somehow immune to the exchange rate anyway, they will just already have sold more stock in prior to the brexit vote.
 
Of course, perhaps people SHOULD ask why go full frame. It's certainly not a panacea (been there done that, hated it).

the bokeh is appalling

The 56mm APD is the ultimate tool for this requirement, however it is not cheap.

and no shoulder surgery bills either!

The distortion corrections are precisely due to the optical problems. The camera is having to manipulate the pixels to remove the distortion issue, a process which gets more extreme as you get to the corners. It's also boosting the gain in the corners to counteract the vignetting, which leads to noise.

I don't need anything more than my X-Pro1 provides me already, and I don't imagine this camera would make a difference to my photographs equal to the cost of upgrading to it. The list of improvements is long but relatively incremental; I'm sure it's a better camera but I just don't do the kind of photography that would benefit from the improvements.

Being an APS-C lens (or mirrorless) won't help much with that focal lenght and maximum aperture. I think that has been discussed somewhere on the forum already, but I'm in the mood for it now, so everyone who does not want to read it again forgive me (or quit now):

A very big chunk of the weight of fast primes are the lenses' front elements. A 200/2 lens always needs a front element with at least 100 mm (+ a bit) diameter, no matter what the format of the sensor/film in the camera is. If you look at the AF-S Nikkor 200 MM 1:2G ED VRII, for example, you can see that behind the thin, flat protective glass element in the front, there are 3 giant, thick lens elements (2x ED convex,1x normal concave), which can't be reduced in size. Those three lens elements alone are probably responsible for 1/3 of the nikkor's weight. (They should be about 10, 20 & 15 mm thick and have a diameter of about 100 mm, roughly estimated)
They have to remain their size because of the way light travels through the lens. There's a nice image on wikipedia that I'd like to borrow for this explanation. I know it's a microscope and not the nikkor's structure, but nearly every (photographic) lens works the same way, and due to the microscopic nature, the object plane is close to the front element which helps a lot with visualising the explanation:

(source: https://upload.wikimedia.org/wikipedia/commons/thumb/e/e0/Microscope-optical_path.svg/2000px-Microscope-optical_path.svg.png )
 
Take a look at the lower marginal ray (green). This describes the path of the light from the lowest outermost point in a real scene the camera can "see". You can see that every point (in the real scene) reflects light in every direction. All the light that is reflected towards the front element of the lens, up to a certain point where the incident angle becomes too flat, is now collected by the front element, thrown somehow through the whole lens and focused back to one single point on the sensor.
This means, if you reduce the size of the front elements, you gather less light for each single pixel instead of cropping the frame, which makes the lens slower, no matter how big the aperture is.
You can, however, reduce the size of some lens elements deeper in the lens. The thing is, they are a lot (!) smaller already, so you don't save much weight by that. (again, the picture does not represent the 200/2s structure)
I don't remember if the Canikon 200/2 are real telephoto designs, but if they are not Fujifilm could spare some weight by building their's as one and reduce the lenght of the lens body (and compensate for their shorter flange distance, which would have required the lens to be longer than the Canikons). But again, not much to be saved there, and it would probably demands more glass, which compensates for the lighter lens body.
 
With all that said, I think Fujifilm could make their APS-C 200/2 a bit lighter than the FF 200/2s, but I don't think they can shave off more than those 300 - 400 g I mentioned earlier. (well, of course I hope I'm wrong).
Fuji's own 100-400 is an example of this: 1.37 kg vs 1,5 kg for the FF counterparts.
 
The often praised APS-C size advantage comes into play when you compare an APS-C system with a FF system that gives you the same angle of view. (200 mm vs 300 mm, and so on). But most people, although realizing and acknowledging the DOF difference between a 200/2.8 on APS-C and a 300/2.8 on FF, don't take into account that the ISO rating already compensates the loss of light every pixel has in the APS-C system vs. the FF system. That's good, because this way, ISO, shutter speed and aperture can be used globally and interchangeable, and that is also important for flash photography. But the size and weight saving of an APS-C system is bought by higher shot noise (worse signal-noise-ratio). This can be partly compensated by faster lenses, like Fujifilm did in the past (and only up to the limit of the full well capacity, limiting dynamic range). But then, your APS-C lenses are just shorter and fatter than your FF lenses. Knowing that sensor developement marches on with great steps, I still think Fujifilm did the right thing with chosing APS-C. But one can't just ignore the fact that a FF sensor of the same generation will always offer better noise performance and a larger full well capacity.
Uuh.. well, I think I started to blabber in the last paragraph. Please pardon me, it's late where I live.

and no shoulder surgery bills either!

As usual, the best advice is to choose the lenses you require first and foremost. The system naturally follows from that choice.

and no shoulder surgery bills either!

Nobody asked for this

It was born perfect :-D

I find the idea that a fine jpg is undesirable due to lossy compression frankly ludicrous. Please let's not fall into the audiophile nonsense trap.

For shots of the kids, I'd go for the 56mm. It's not a good lens for adult headshots—a bit too wide—but for kids it's really appropriate. The 90 obviously requires more light and if you've not used a 135mm (equivalent) before, you'll be surprised at how tight the framing is. The 56mm will give you fewer problems in terms of room and light, and it's still long enough for some significant subject/background separation.

That said, the 56mm is a weird beast. Some people treat it like it absolutely has to be used at f/1.2 at all times, but other people will tell you to always stop it down to f/2.8 or f/4 to actually get the sharpness out of it, which is what it's become more famous for. Some people will tell you 85mm is too wide for even kids' portraits, other people will tell you 85mm is too long for practical use outside of a studio/stilted portrait environment. The 56mm is absolutely beloved by some people, but then other people doing the same kind of shooting will use it and think it's a bit pointless. 85mm came along as a portrait focal length because it is more casual than the old standard of 105mm but more intimate than a 50mm, but not everybody was happy with that compromise.
Personally, I've had four copies of the 50-140mm, two 56mms, and one 90mm. In terms of objective image quality, they're all equal; the 56mm is noticably softer wide open than the 90mm, but that's the price you pay for a-stop-and-a-third more light. For sake of equality, if you stop them all down to f/4, they're all the same. There is no objective reason to pick one over the other. Your own preferences for a certain focal length are all that matters.

You have a 50mm and 60mm on your Sony system, which has the same crop factor (1.52x). Look at your photos with those two lenses and see if you're happy with that ballpark, because the 56mm is obviously in the middle of those two.

They're playing us like a fucking fiddle!

Congrats

samyang 8mm fisheye at f22 focusses at the speed of light

samyang 8mm fisheye at f22 focusses at the speed of light

You can set OIS to 'shooting only' so it's only active when the shutter button is half pressed if you want.

samyang 8mm fisheye at f22 focusses at the speed of light

I'm going to need to see Ken Rockwell's opinion on this before I draw a conclusion.

I'm going to need to see Ken Rockwell's opinion on this before I draw a conclusion.

But when you're instead just wasting time to recreate the effect that's already there, it invalidates the argument. The whole point of film simulations is to lock down those flexibilities that we enjoy today to a specific set of values that people shooting film had imposed on them in the past, for a specific look. If you need to post process the picture before applying the film simulation then you've completely missed the point IMO, and you're at best shooting 'fakros'.

I expect that just like the 35mm it will be smaller, cheaper but not quite as good; the f/1.4 23mm is a very well corrected lens that only measurebators can criticise.