I got mine used, lucky I got one with pretty much in mint condition, and a tripod mount collar ring as a package, which I found useful since it is heavier than the camera body I use. The result images are sharp from wide open with minimum vignetting, AF is fast and the ring itself is smooth with subtle dampening when hitting the focus range limits. I don't know is it just mine being old (or worse still, defective from the factory) or just the characteristic of it, the zoom ring is too light to rotate. Though that said there's no zoom creeps at all (maybe just an internally rotating zoom lenses characteristic? idk, this is my first lens with that feature). The IS is effective, but my God it makes such an annoying high pitched sound when turned on. But again, I don't know is it just mine being not new or actually a "feature" of this lens.