I used one of those a while back. All that really sticks out in my mind is the zoom creep! Anything more than a slight gradient and away it goes. It could traverse its whole range of focal lengths in a couple of seconds and if you had the camera hanging around your neck it was constantly at 210mm.
Not really a problem if you're likely to always keep one hand on the lens, but if you're planning to mount on a tripod, pan with one hand and operate the shutter with the other it could p*** you off a treat.