I bought NASCAR 09 with trepidation as the 2008 version was awful, with terrible AI. However I was pleasantl;y surprised with NASCAR 09 as a whole.
The handling model had been changed slightly to give the cars an extremely driveable feel. And once I had binned off my previous NASCAR game driving style and decided to drive like a real driver, i found it a great challenge and a fun experience. Yes, to some, NASCAR is 'dull', but I'd translate that into a need to be consistent.
Also, at the end of a 100 lap race that you have been leading most of the way through, when you are on worn tyres being caught by a rival it turns into an exhilarating experience. The AI is aggressive and will try to overtake you, but you need a decent setup to even compete with the leaders on most tracks. Managing the tyres is key to success.
There are still issues though. The AI is terrible on road courses, the lack of official car manufacturers is disappointing, the damage model is shoddy compared to true next gen games, and it can be difficult for new players initially.
I'd recommend it for fans of NASCAR or for people wanting a different driving challenge. Especially if you can get it for less than 20 quid. :) They aren't making another one in 2010, so grab this while you can.