i use a dyno dynamics dyno... i really like it alot of tuning, all the part throttle and ve tuning is super nice because i have so much control via the eddy current... but i have severe traction problems on high power cars, i literally run the straps up through the middle of the rollers and pull the cars straight down into the rollers and i still have traction issues.... another issue is when i have issues, their customer service lacks a little and most of the people that really know anything about the dyno are in australia...
i am in the market for another dyno, i will be looking for a large single roller with some real good steady state control