Everyone says Jennifer Hudson stole the entire movie and after seeing it, I agree. I didn't think every song was good but there were quite a few highlights. If you go to iTunes and listen to the original broadway recording, you'll hear a more soulful rendition of the songs. The new recording is very polished and "hollywood". They're both good but if different ways.
Go see the movie for Jennifer Hudson's performance if nothing else. I'm not a fan of Jamie Foxx and I'm still not. He was ok. Eddie Murhpy was actually really good. He wasn't doing schtick or campy which is a relief!
Beyonce's role was quite minimal and there's one scene that was stellar.