all you are going to get is opinions with a thread like this. i had a SPS 66, i liked it, huffed and surged a lot (not II's fault) started dealing with htt when i went to twins, i feel their customer service is a ton better and there SS housing is slick. both companies base their turbos off the same platform, call them both and pick the one you like. my vote is HTT and the prostreet. but like S G said, twin it!