All cameras are boxes that keep the light out until you open the shutter.
Nikon F, F2, F3, F4, F5, F6 are total crap without a good lens, and most importantly a talented operator.
Forget about the camera. It is not a symbol of your artistic talents. It is only 'male jewelry' to be worn like a necklace.
So get a box that works for you, not what others tell you. Then spend real money on lenses for they sharp the image to match your creative vision.
I've used all the above cameras, except the F6, professionally. I prefer the FM2 over all of them.
Here's a truncated list of my clients if you don't trust what I've said (the list does not include the 4 years I was a staff photographer and photo editor for USA Today): http://www.walterpcalahan.com/Cheers/Clients.html