I use an FW, I’ve had it since new, maybe 8 or 9 years now. The lens is exceptional. I had one winding problem, the camera jammed up, and I had to send it to DHW in Germany for repair as I couldn’t find anyone in the US that would open it. This was about 5 years ago. Other than that, the camera has been fantastic. I much prefer a meter in camera, and this one is very good, but I find I need to take a reading with the magnifier up and my eye at it, for the cell is in the upper chamber, and stray light from the screen can influence the meter.
I had a vintage Rollei F something, and the FW/FX cameras are a little less silky smooth in winding, but I wonder how much of that is simply volume of use. The latest cameras are very firm and seem very precise in winding, not sure if there are differences in construction in the newer bodies. I have an FX as well, which came to me well used, and it winds a little more smoothly.
The loading of the newer cameras is different, but I’ve not seen any film flatness issues at all.