It all depends on you, the instructor and the circuit Daz. I've done a few and they vary greatly between venue and instructor. Generally if you show you can drive quickly but safely then they'll let you give it some but a few I've done were disappointing. I'd youtube the venue and experience and then choose from there. Prestwold Hall near Loughborough is good. I drove a Nissan Gtr there and overtook everything. But you've got a few nearer. The best advice other than youtube is to decide which car you want to say you've driven.