My brother had a pretty quick GTT (150ish bhp but over 170lb/ft of torque)
Always beat me when mine once standard, but it would have beaten my valver even now (est 160bhp)
Having driven both, the acceleration on the 5ive was definately quicker but started to loose breath at about 120mph, where as the valver can do over 130mph easy.
Also, the 5 handled better and stopped quicker, probably due to his being lower/stiffer than mine, having a big brake kit on it and being a lot lighter.