I haven't heard anything other than it's back seats are "inhospitable" to anybody except small children. It is really speedy, and does save you plenty of gas...
I want a 'heritige' sports car, so I can't get one of those, and if I didn't need to save money, I would be getting a cobalt.
If you want to know anything else take a look here:
http://www.chevrolet.com/cobalt/features/