[S50Sinner]

The S has a taller final drive ratio (3.73), while the 2.7 has a final drive of 4.16, so you'll top out at a higher speed in each gear. This means you'll have slower acceleration and lower revs at any given speed.

You'll probably get better fuel economy and a quieter drive, but that's not really why we buy Boxsters, is it?

The 2.5 transmission has a 4.20 final drive, which would make your car a tiny bit more sporty, but I can't confirm if the software for the transmission control will work, you may have to do the legwork for that one.

All in all, I'd try to find out if the 2.5 is compatible, they might be cheaper to buy and would make the car a little more peppy, otherwise go with a 2.7. I wouldn't install a 3.2 transmission, it'll be a noticeable hit to performance.