I'll start saying that I do not like him as a fella, yet I can see where he is good and what I do not like of him.
POSITIVES:
.Great pass.
.Great strike.
.Pride and confidence.
.No surrender attitude.
.Numbers, he is a player that it's hard to have a season without putting a good number of assists or goals.
NEGATIVES
.I don't like him as a leader, he isn't as talented as he thinks he is and he constantly blames others no matter if a certain bad play it's entirely his fault.
.He's composure as a whole: he lacks it regarding controlling the ball, holding it and distributing it and he also lacks it regarding the way he manages with Refs and his mates.
.He plays too many times in a rush not only because of being direct and goal focus (the good part), but also because he lacks the ability to dribble, to retained it, to find or make the time for another play or distribute better.
So all in all, FOR ME, to make him a leader of any team it's a mistake, yet he has traits that if someone has the personality (and talent) to deal with his Ego in the middle, while having him on check and not letting him "managing" everything, he can certainly work and be a great asset. Even as infuriating as he can become at times.
At the same time, United or any team with him will need to provide in a strict fotoball sense abilities he doesn't bring to the table, combining him with only extremely direct players only + mostly defensive minded ones, not a great mix.
This period in time in EPL, ain't old England style or Serie A in the 90's where we could see a match with Totti on one side launching long balls and Veron on the other doing the same constantly while both teams pressuring the whole game trying "to play on the rival's mistakes".
Constantly risking it in such scenarios wasn't that much of a big deal, since the ball instantly could return to either side. In these days you sometimes can't recover the ball for ages.
Do I think he is a player to built a huge team on him? nope. Do I think he can be a great asset in a strict fotball sense/abilities? Totally...DO I think his ego can deal with that and he'll calm down a notch and become more mature player from now on? I doubt it.