I don't agree that anything over 550BHP is "uncontrollably frightening". Mine is perfectly controllable, without an LSD, and I've driven it round a track with a professional racing driver to know! I had something very similar. Previously, my car was running 510BHP and a couple of years ago I was sat at some lights next to a 2009 Leon Cupra R thing, with centre exhaust. Didn't give it much welly off the lights until I realised the Leon was pulling away. By the time I realised and started nailing it, I nailed it but I just could not make any more ground than the Leon. Had I known and given it a proper start, things would probably have been very different! Indeed now running at 580 > 600, a few months back I saw it again and tried to goad it into a TLGP but he/she wouldn't play ball. Why? Who knows. It just goes to show though that anything can be fast.