A really good all-around lens. If I had to take only one lens on vacation, this would be it. The combination of wide angle and zoom make it very versatile. Some reviewers have complained of lens creep - the model I received had a manual lock that prevented creep, but you have to unlock it every time...
The IS function works good as long as you're not over-caffeinated, I imagine a system built into the camera body works better though; Decent focusing speed and low-light performance; Great zoom and wide angle.
Heavy; Obvious vignetting; Obvious spherical aberration, Power consumption is high with the IS switched on, and ***the IS does not seem to shut off when you turn the camera off!*** I have to shut off the IS independently; of the camera power.