Just ordered this as I have been looking for it cheap. I had this on the Xbox 360 and thought it was a decent game. In my opinion this game is better than Need for Speed Pro Street.
If you own a Xbox 360 and are connected to Xbox Live you can use your Xbox 360 Gametag and get some Achievements. Even if you all ready played this game on Xbox 360 you can get this and get the Achievements as its classed as a different game.
Well worth £6.
Edit: There is a few vouchers around for CD-WOW to get it even cheaper and don't forget 4% cash back with quidco.