I saw it with a friend a few days ago,and neither of us enjoyed it at all,it was all a bit too weak,plus it was very obvious what was going to happen at the end(dont worry,no spoilers folks).
Then again it might have just been weak "by comparison" since the day before we had seen Gnomeo and Juliet which was very original,plus all the music was by Elton John,while in Rio it was all a bit...lame...to say the least,LOVELY vibrato on Anne Hathaway though,I didnt know she could sing like that.
Different strokes for different folks though,whatever floats your boat I guess but we personally didnt like it