I have an M series from the early production. I can't say how many rolls I've shot but it's in the hundreds. I have nearly all the accessories and extra inserts, I even have the original case. It's a fine camera. I'm partial to it despite having to tilt it for vertical shots. It's never failed in me. I've replaced the seals once and that's it. Have fun with yours. I did but a Pro model a couple years ago. I have a nicely equipped RB67 Pro S too and the revolving back is a delight.
My preference these days is large format though.