As for the willy waving competition... I think Gilly has made the best point (although it's not the point he was making).
I have a mk6 gti revod atm.. and a mazda3 mps as a reserve car. If you want to go in striaght lines then I would happily turn up with the mazda and its 300+ bhp. Alternatiely we can visit a track and i will bring the GTI. Either way I dont think I would meet with a kid to prove a point... everyone gets a point in the willy waving club
More horsepower isn't always better. That's why I'm presuming the MPS is for straight line fun and the GTI for the track.
Going back to the OP again, in the situation of trying to catch another car between roundabouts (on the track obviously), there's no hard and fast rule about what car is quicker. High end horsepower could be beaten by low to mid range torque. A more powerful FWD could be beaten by 4wd traction but then a powerful buy heavy car could be beaten by something lighter and nippier.