I bought this lens recently and had the chance to shoot an event with it with my 60D and T2i. My biggest gripe is the focus ring. Firstly, it's a short turn range, like 45 degrees or less. When I use my Zacuto Z-Finder to get in focus, the slightest turn will make me miss the focus point.

Another gripe I have, and probably even worse, is that the focus ring feels rough. I'm not sure if this is my copy only but I seemed to have this problem with the Tamron 28-70 2.8 I used to have as well. By rough, I mean you need to apply a bit of force to start turning the ring, and when it turns, it feels like there's sand under the ring, like something's grinding while you turn.

Both of the factors above make it difficult to use the focus ring for any effects, like a rack focus shot or a long focus turn to/from infinity.

I have not noticed anything about VC noise or autofocus noise if you take stills, since they didn't matter to me at the time (I was shooting a loud event anyway).

The other lens I was using for this event was a friend's Canon 70-200 2.8 IS, so I was definitely comparing it to that. The focus ring on that thing is amazing, and I felt like I could do so much with it. But that might not be a fair comparison...

I wouldn't mind hearing from other owners if they experience the same thing.

I'd agree about the short turn radius - it's short.

I use a DIY focus gear (essentially a wheel pressed against it) and it works well, but I could see how a geared set might not love on the short turn.

Mine's plenty smooth though - if continues to be an issue, you may want to exchange it.

Seems like a nice lens. But I keep getting a lens communication error when I go from video mode to stills mode on the 60D and try to take a picture.

Hmmm.... that sucks. I know recent T2 firmware has addressed some lens compatibility issues - I wonder if the same is true for the 60?