I've got a set of powervisions on the 97 and the bestops on the 99, so I can do a pretty good side-by-side comparison. The powervisions are smaller, but in many cases they are probably plenty big enough for whatever you want to do. The 97 is my daily driver and the size is perfect for that truck. My 99 spends the whole summer with the slide on in the bed, and for that use the huge area of the bestops is great. I just took the camper off and the bestops are overkill when not hauling anything. As far as looks, I would give the nod to the bestops - they are in proportion to the truck. The powervisions stick out just under 15 inches from the drivers side of the truck, the bestops are 16. 5 (both in retracted position). Even though its only 3 inches total, the bestops have a little more of a pucker factor going through tight drivethroughs.
Both products are well built and solid. let me know if you have any specific questions about the 2.
-Vic