The FSR's are quite a bit heavier than the BX. The ASP only weighs about an ounce and a half more than a .91 4 stroke. I have an ASP and an FSR and love them both. If I were needing another 1.08, I'd have to go with the ASP because of the price. I don't know about the RED heads, but the series 3 ASP 1.08's have an OS 7D carb on them.