Brands GP is a great circuit - pricey I agree, but its worth doing if you've not done it before and getting a sub-£200 price tag is worth taking if you've not sampled it.
Brands GP is a very fast and flowing circuit some mad 110mph + bends and well worth going if you can stump up the wonger. Similar I suppose to Donny and Oulton.
Cadwell is a very different track, great all the same, but suits a smaller, quicker turning bike - like a Monster!!!!!
Tim
[Edited on 3-2-2005 by Rattler]