I can't believe in Barcelona completely after seeing their performances against big clubs. They have had really unsatisfying results in those games. This was even the main reason why they couldn't qualify from their Champions League group. Xavi's priority should be to fix this first. Because they don't have any other issue than this actually to be successful in multiple tournaments.
Manchester United are just as usual. They are still not a very consistent team. They are dealing with big issues about having comfortable wins. Because their attackers are not having a great time. If this scenario continues they are likely to stay as the underdog. I still see Barcelona one step ahead as long as they deal with their main issue.
You're not wrong to say Barcelona is better than Manchester United now, because I see it that way too. Barcelona's only problem now is that they can't be balanced against teams that have the same or even better strength than them. Bayern Munich, obviously better than them so that in the group stage they easily won matches in 2 meetings. While Inter Milan is a team that cannot be said to be better than Barcelona, but they are able to make them better on the field.
At this meeting, I said that Manchester United is almost the same as Inter Milan, so they (Barcelona) have a better chance.