I fully understand how neutrals might not like his understated personality but if you were a Barcelona fan you would love it. The only complaint from Barcelona fans I read is that he is a little closed off to them but that is his choice. And while it happens all the time with Messi I would be utterly shocked if he was hiding craziness, especially with the press all over him it would have come out by now (people for years have been calling Armstrong a scumbag).
No fuss, no drama, little ego (there will always be some by default of being the top striker for a giant club like Barcelona), just winning for the team and playing the best he can every game.
While that might affect his form when losing; ie not enough fight, that is also a strong double edged sword. One he night might inspire a great comeback the next might get sent off after twenty minutes and your team has no hope.
Personally I love the no drama from him as I can relate, I want as little drama in my life as possible, just needless, unwanted stress.