A few years ago I dropped my well-used Nikon FE while I was crossing the street. 4 ft drop onto concrete put a BIG dent in the prism housing. The attached 50mm lens was OK, but looking thru the VF the image was distorted. I was sure I had shattered the prism, but removing the lens I found that the mirror was half raised, so I was able to push it back down into place. I was able to continue shooting that day and never encountered any problems with the body afterward. I am fairly certain any of my F or F2 bodies will be able to survive the same abuse just as well, or better. I have an F2 that looks like it went thru a garbage disposal and is mechanically perfect.
That being said, I love my M2 - it's a joy to use a 50-year old mechanical marvel like this. Same feeling as shooting a plain-prism Nikon F, simple and uncluttered and neither is a toy by any means. Just use the tools that fit your hands and suit your style of shooting, regardless of price or reputation. Both cameras were engineered and designed to do one thing very well. I don't expect that the RF of a Leica will fare as well after the impact that my FE suffered and it certainly wouldn't be as cheap to repair/replace.
Only you know what you need. My ideal shooting day is an urban walkabout with an M2 and an F, a few lenses for each, a lot of film and a few good cafes along the way. (If I have space in the bag I may bring along a Rolleiflex!)
Go take some pictures!