I don't have the 7 but have a slightly older 8000i. I don't think it supports the SSM lenses. It does have a very nice, if plastic feeling, 28-200 Tamron lens. The auto focus is quite good IMO. The lens is also very sharp for most of the range. A little soft near the 28 and 200 settings but not bad.
I was going to get a Tamron 28-200 and read a lot of awful reviews on it dyxum. Maybe they just got bad copies? I was looking for a good walkaround for my Maxxum 4, it's my walkaround 35mm because it weighs next to nothing. I have the 18-270 hyperzoom for my Canon Digital Rebel and was impressed with it.