Very compact lens, seems to be made well. I've used it for about 4 months and maybe 30 rolls with my M3 and an M adapter. It's a great piece of glass, very sharp when the focus is on, even wide open. Stopped down the contrast goes way up, so if you shoot Velvia or over-agitate some Bluefire Police be careful with the shadow exposure. Wide open it has a nice look with very good bokeh. Some flare using the tiny stock hood, but it basically disappears when you stop down past 8.0 or so. Great lens for street shooting - it's tiny, unobtrusive, sharp, 35mm stopped down to 11 or 16 gives you plenty of DOF for set-and-forget scale focusing. The focus knob is pretty small, usable but I like rings. Once you use this lens you'll realize that a ring wouldn't really work, the barrel is just too short. Nice aperture controls, not very hard clicks but hard to bump by accident.
Overall, a great lens that I would recommend to anyone. The low price sweetens the deal.