For all its positives the lack of attention to detail derails what could have been...
What Eutechnyx/Activision does best is presentation. The cars and tracks look great, and the menus have a very modern, spunky, personality akin to the Dirt games. The cars handle fairly well and I like that they left out the pull-to-the-left on straight-aways effect. While I understand that in reality the cars are set up to be biased towards left hand turns, it can be difficult to compensate for using the standard game controller and would make online play even more of a headache than it already is.
All the tracks are in the game, including Kentucky, and look good. Most of the drivers are in the game (though a couple of notables are missing), with some having multiple paint schemes. In addition, a 2011 update was released in July that included updated cars/schemes for the current year, a nice bonus (though well delayed beyond what was initially promised).
A striking omission is the rear-view-mirror. Instead, an odd radar is used to display cars near you. It's perplexing to think that we are in the HD generation of gaming and there can't be a mirror? From what I heard this was due to slowing the framerate? Whatever, practically every racing game has a mirror, this shouldn't be an issue here.
Concerning offline career mode, some will hate it and some will like it. Basically, the developer decided to go with a one-full season schedule and that's it. So if you were used to the career modes that spanned multiple years like in previous EA NASCAR games, then you will be disappointed. On the bright side, however, you have the ability to alter all settings at any point in the schedule. Competition too tough to tame? You can drop the difficulty. Too easy? You can up the difficulty. Though the AI is ok, if you run long enough to have pit stops the computer does some very strange things. Yes, pit stops are on auto. I suggest running the races short enough that you don't have pit stops, they're simply not fun or engaging. That said, running in the pack can be fairly fun and the AI cars do respond to your presence for the most part.
As for achievements, they mostly involve winning everything in the game, boring.
Sadly, online play is just short of broken. If you just want to hop on for some shootouts its fine, assuming you happen to get matched with some respectable players. However, it is far from league-friendly which is a real shame because for most experienced NASCAR gamers that's exactly what you're looking for.
So if you're a NASCAR fan looking for a causal racer then this game is ok, but if you are a hardcore player I would suggest looking elsewhere or sticking with the PC entries.