They're as reliable as the day is long, small, light, and have a wonderfully accurate meter. What's not to like? Well, the shutters tend to be a little noisy (none of this Leica "snick" business), but that seems to vary from camera to camera. That's not a big deal anyway, unless you like stealth stuff. Oh, and they will hang at an angle and dig into your back when you have them on a strap unless you have a heavy lens on them, or you buy a $30 side grip, which works well but prevents you from carrying it in a half case on a strap. I went through a LOT of screw mount Leicas and the like until I got tired of using ancient gear that almost always needed a CLA that cost more than the camera did. Just buy the R, screw a lens on it, and you're ready. Build quality is not Leica like, but it is fine.