They can get pretty firm depending on which kit you install. If you put a shift kit in it can and has made them shift to harsh depending on the electrical changes made. I've done a few TRANSGO HD2's, and they shift nice and crisp. If you install a corvette servo with it, you need to change the accumulator housing in the valve body to keep it from slamming the 1-2 shift. The key is to do one or the other(or make sure the electrical modifications are setup for the shift kit). I personally prefer to change shift firmness hydraulically instead of electronically, and is how I do them. The shifts with your 05 aren't going to be super snappy regardless of what you do because of the ETC and SEM built into the PCM programming. Most tuners still keep alot of defuel in for trans protection which keeps a soft shift. Depending on the shift kit it can bump up line pressure, as well as decrease shift times by altering the accumulator setups. About all a shift kit is going to do for you is to bump up line pressure some more, and change lockup to an on off instead of a pulsed style where it lockups soft.
