Right im going to get slated for this, but in my opinion I prefer Him to Messi. For a few different reasons. obviously when he was at the rags I hated him, as did anyone who wasn't a rag. But since he moved, my dislike for him simmered and I could appreciate his footballing attributes. The following is just my opinion, but I think Messi is just as ego centric sulky woman as Ronaldo is. But out of the two of them I would prefer Ronaldo to messi at city (if his love for united wasn't so great), but his heart for English football will always be at the swamp at that's fine, he is allowed to love that club.
I think Ronaldo is stronger, he is just as skilled as messi (Somedays messi better somedays Ronaldo). But crucially I think it comes down to the risk with the price lets say they both would cost 100mil (I know this isn't the case just a ball park figure). In the premier league Ronaldo has proven his competency whilst Messi has not. Messi seems to get injuries which Ronaldo doesn't.
I look forward to having a temporary ban for this opinion.