I own all five variants. The F5 is definitely the best AF body of the bunch. For MF, the F4 is pretty hard to beat. Sure, it's fully electronic, unlike the F, F2, and, in some respects the F3, but it has the best meter display, features, and ergonomics for a MF body. One that just happens to do AF as well. It also does have some of the modular features of the earlier bodies, where you can delete the high-speed battery packs (MB-21/23) and go to the MB-20, which has a thicker grip, but makes the camera lighter and shorter. That helps make the camera a little less obtrusive and easier to handle. My plan is to pick up a MB-20 for my F4, turning it into a standard F4, instead of the F4s version, since it's not my main AF Nikon body anymore. My larger hands like the thicker grip, since it helps stabilize my 300f4.5 EDIF better. The F4, like the FA, will matrix meter with factory AI and AIS lenses, unlike the F5, which either does the 75/25 centerweighted metering or spotmetering with MF lenses. It wasn't until the F6 that Nikon had a film camera body that could matrix meter with non-CPU lenses.
The F4s feels a bit heavier than the F5, surprisingly. But, the F5 is taller, closer to an F3HP/MD-4 combo in height, but probably not as tall as the F2A/MD-1/MB-1 combo that I used to have. Still have that body, but no longer the drive.
-J
