Not a fan of the A90 styling at all but you cannot knock the gains. Take the M240i B58 for example and the Big Boost kit and I quote:
BigBoost's car: BMW M240i
Stage 3.4 turbo
Current B58 record holder: ̶5̶3̶4̶, ̶5̶6̶3̶, ̶5̶7̶1̶. Currently: 711 WHP
5.41 100-200
10.85 @ 135 1/4 mile
....so that’s running a far larger turbo system with over 700rwhp and getting a shade less 1/4 than an A90 with a downpipe, tune, MT tyres and some higher octane fuelling. That alone says the platform of the A90 is going to be pretty special once others have modified more extensively. I’m actually really looking forward to seeing what these beasts can do, even if I have no plans to ever get one.