Howdy Daniel: I shoot with F2s and Leica M-6s so I can't speak to the Leica R series. But the F2s combined with Nikkor glass are wonderful cameras. They operate smoothly and pretty quietly, you can use them to pound fence posts with, can still get them repaired, and if you happen to have paws that are as big as mine, a pleasure to have in your hands. Just a sturdy, flexible, well-made piece of equipment with a ton of available accessories and lenses.

BTW, you can find some excellent deals on F2s at KEH.com in Atlanta. They have a 30 day warranty and 15 day full refund policy. Also, get the Moose Peterson "Nikon Compendium" to give you some historical aspects of these things and help you navigate the vast sea of Nikon. ;>)
Take it light.