G.R.,
I use QA1s all around and like them. They are 12 way adjustable. The Carreras are also very good and I considered them before the QA1s. In my case it was mainly how quickly I could get the set. I talked to both tech lines and they both told me pretty much the same so I don't think you will go wrong with either brand. Iam not sure how the Carreras adjust but the QA1s have a small knob at the bottom that you turn a click at a time to stiffer on soften the rebound. I run mine on 4 around the streets. Anything above 8 and it is like riding on a straight axel with no springs.
Ron
