Originally Posted by wstar

It's actually a much-improved transmission over the 5AT, there's some technical whitepapers out there from Jatco (the mfg of both). Mostly it's about improvements to the shifting speed/firmness, the downshift rev matching, and the full lockup stuff. For a fluid-drive true auto, it's really one of the best units out there. It's almost good enough to be a poor man's DCT/PDK type thing (which is what I used it for), but obviously a real DCT would be better.

6 and 7 are definitely cruising overdrive. Even 5th doesn't have a lot of umph, and I'd call it an "overdrive" too at the 7AT's rear end ratio, although if you plan to be full in the throttle past ~120mph you'll need to accelerate in 5th as well.