Sleeper05

SCT is nicer on the tuner. It has a pre-programmed nature that makes it much easier to make quick changes. This is the primary reason it is more prevelant.

Caution

I have both the SCT & Diablo -- The Diablo was easier, JMO

androdz

They are all the same. Go with what ur tuner uses. Mail in tunes are nice, but remember they have to make a tune that works for me(puerto rico) the same way it will work for a guy that is in alaska and a guy that is in africa. So they tend to be a tad less aggressive.

Andrew