This weekend they wife and I attended a Tamron event. It was the first of their State Parks workshops. What was so nice was there were basically no speeches (yea). We had the chance to shoot most of the Tamron lineup in the park or at Anna Rudy Falls (Federal property) on the mountaintop above the state park. http://www.tamron-usa.com/events/parks.asp I must say I was very impressed with their 24-70, 70-200, 200-500, and 180 macro. I really like the internal focusing (IF) concept where all the moving parts are inside the main sleeve. It minimizes dust getting into a seam between two both halves. We had the 18-270 (not a higher end SP lens) as a good walkaround for our 7Ds. I am seriously considering changing to 24-70 as my walkaround on 5DII instead of my 24-105. I like the faster speed and VC on the 24-70. In general how do the rest of you perceive the Tamron lens lineup, especially the SP higher end lenses?