I have the sport seats re-done in katzkin leather outers and suede inners, and they are super grippy compared tot he stock vinyl that was on them. I like the bottom height i will admit, and luckily most of the lights here are low enough that i dont have to contort to see them out of my windscreen, or super high, and i can see them through my sunroof :P (not an option for everyone...)

 

There are significant differences in "stock" seats - the base Sport seats are very different from the "same" sport seats with leather or leather/cloth and the liumbar adjusters - I swear they're different frames, even. The only seats I've had that fit better were the Recaros in a previous early '90's GTI/GLI.

In the R56, they're even MORE different. Well worth the $ to get leather/cloth compared to the stock seating.

Of course, all butts are different...