Which is not a bad thing, since he's an elite striker, but he's not versatile. Madrid was tactically limited because up top they needed to keep Benzema as target man, and feed Ronaldo coming in from the wing. It worked wonders, but it also limited the way the midfield and attacker positions were played.

Messi, despite the "but it's the same club" argument, has played more positions and tactical systems than Ronaldo. Rijkaard, Guardiola, Vilanova, Tata Martino, Luis Enrique, and Valverde have played him in different positions and asked him to do different things for the team. And he constantly delivers.

Here's a nice chart that summarizes the difference between Messi and Ronaldo. The latter needs the team to play for him to be effective. Messi not so much.