Tom, I have a friend who has one. These cars are very quick for a V6. It helps that they use twin turbos. 425hp, 0-60 in 3.7 seconds. Since I sold the Cobra, I have added a Noble to my list of candidates for the next toy. Of course there are a few models of Ferraris on the list as well.
Never owned one but have driven it and it is great! Seriously quick, but the handling is what that car is all about. Contact Dean @ 1gracing he'll setup a test drive for you. http://1gracing.com/
I have one. They're loads of fun. It's quite a bit of car for the money, but you don't get the name recognition of Ferrari.
I've never owned one, but I drove the M400 and it was fantastic. Loads of intoxicating power at your beck and call. If you don't worry about nameplate envy, the Noble provides the performance of an F40 for the price of a 355.