I've only tried 2 different universal clip-on's. When I had my Tacoma I wanted something that looked decent. So I bought these. http://www.amazon.com/CIPA-11960-Pre...4584293&sr=8-3
Short easy review "They SUCK!" Little longer review. They go on easy and don't vibrate much. But that's where the good ends. They are hard to adjust and don't stay there for long if you can get them adjusted . One of the mirrors fell out of the housing and broke when I was trying to adjust it once. They are away to small to be of any use.
Then I tried these http://www.amazon.com/Fit-System-389...4584293&sr=8-1
They don't look as nice but they go on easy and are much easier to adjust. They also have a much bigger mirror which results in a better viewing area.
Now that I have my Ram (also a sport) I still need to use an extended mirror but haven't put them on this truck yet. I've towed the camper twice with it and I really should put them on but hate to deal with any clip-on. And I don't like the looks of the stock tow mirrors. If I towed the camper enough I would go with them but I don't so I'll deal with the clip-on's.
Bottom line I'm not sure there is such a thing as a good clip-on mirror. But some might be better than others. Good luck finding one that will work for you.