I've driven a 300bhp+ cossie, passengere in aeveral 500bhp+ cossies and they're great fun, but I've also done alot of miles in a 400bhp c5 corvette and a caddilac ctsv (6.2 supercharged v8 556bhp) and they were on another level, especially considering they were bog standard cars. Is definitely go for a sorted v8 over an equivalent power by, or any turbo'd 4pot.