Is he underrated?
Definitely.
Don't really think he's underrated. I think pretty much everyone appreciates he's class.
Love the impact he, as a 'right back' (I know, but still) has on a team going forward. Yes, he has brilliant players around him but his level of contribution is such an asset for Barca. The sheer thought of knowing that at any time he's running past you but being blind to it is a ballache for the defending team in itself.