I am finding my new EF-S 18-200mm IS lens quite slow to autofocus. Anyone else notice this or is it just me?Quite slow is not a very descriptive term, does it tale 0.5 sec, 5 sec, or 5 minutes? Are you focusing from mfd to infinity, or from 5 ft to10ft? You could have a bad lens, or it could be normal. We really can't tell, and assumptions are often wrong.
Comparing focus time with a lens like the 50mm f/1.4 will make the 50mm look fast, it does not move the internal mechanism nearly as much as iin the 18-200.
OK, I only had this lens a short time and no other experience with a 11X zoom. I bought Canon (over Tamron, et al) as I thought it would be superior (reviews certainly preferred it).
It was an internal evening shot last night on around 170mm photographing my wife (before and after shots) of a cosmetic treatment. Distance to subject was around 1 to 1.5 metres (didn't measure it exactly). To begin with it would not focus at all. So I exchanged it for the EF 75-300 mm kit lens, which instantly focused. OK obviously not a problem with the camera, then cleaned the contacts on the 18-200 lens and tried again. This time it did focus but took quite a while compared to the 75-300. How long I don't know for sure as I didn't time it.
Sorry for the lack of precision.