I've always been in the Messi camp but performances like tonight's make me see some logic in the arguments
@Peyroteo puts forth. With Messi, it often seems like he has a limited impact on a match when he isn't doing something magical in possession. Now because he is so much better than everyone else in possession and because Barca often dominates matches territorially and in possesion, he usually gets enough of the ball in dangerous areas to make a difference even without much movement or effort on his part.
But in matches like tonight's where Barca are on the back foot a bit and aren't dominating completely, those deficiencies in his off the ball movement and his loss of pace over recent years become more apparent. It's one thing to say that Messi is the best dribbler/passer/finisher on the planet but having the potential to do those things with the ball doesn't count for much without the movement or pace to receive possession and find space to actually demonstrate that ability.