With CG animated films becoming more popular than ever, more studios are investing into this area. Pixar and dreamworks set the standards very high and a lot of CG animated fall flat from the start.
Rio is one of the rare exceptions. Being from the creators of Ice age (I'm not a fan of that franchise) I was a bit skeptical. However the film is full of luscious colours ,as you'd expect being set in rio, and had a charming story that had some good laugh out loud moments.
However there is a flaw with the discs and I looked online to see if I had a faulty disc but it seemed to be a common fault. For some reason the film can freeze for a second or two at random spots (they won't necessarily be in the same place if you re watch it). It's kind of fustrating they allowed this to happen and perhaps an update to your blu ray firmware could and possibly may already be available to eradicate this issue.