I could go on forever, really, but at last I'd mention consistency. Maradona was consistently the best player in the world from 1983 to 1992, that's almost 10 years, even though he was noticeably reduced from 1990.
Sorry but at least this part is very very wrong. I watched Maradona play live for 2 seasons and though he was a genius, he wasn't consistent at all and is considered a flop in his 2 seasons at Barcelona, specially regarding his mentality and his total lack of discipline. Even if his stats were ok, they were nothing extraordinary and he had clashes and problems with evryone at the club.
His 2 first seasons at Napoli were good, but not absolutely amazing. His explosion comes from 1985 to 1989, and that's it. Because what happened after that was the chronicle of a fall and unfortunately a terrible way of ending a career.
I would say that at best, Maradona performed at the highest level for 3-4 seasons, and never in the European Cup. I know they were other times and playing at Napoli has a lot of merit (but the same could be said about hundreds of great players) but in terms of club career, he hardly had the impact of Pelé, Messi or even Di Stefano.
So let's compare him to Messi (imagine Messi's career ended yesterday). Messi has already delivered more consistent performances than Maradona in his whole career. He has been influential in more trophies and broke more records, solo and team records. The only difference is the World Cup '86, which really turned him into a legend. But we're talking about 4-5 matches. I think the whole career speaks a lot more about a player than a select group of matches. World cup matches in my oppinion are overrated.
Important: I've watched both play live. Messi has been and is as influential (or more) than Maradona and for a longer time. You will agree that Messi most of the time plays as an offensive midfielder and the fact that he ends up finishing the play is just a testament for his amazing skills and influence on the pitch, where he can roam and fall back or go up at will. If you don't think Messi takes the same role as Maradona many times then you should watch more Barça matches.
And finally, in each of the last 5 seasons Messi has scored (a lot) more goals and delivered (a lot) more assists than Maradona in his best one.
Messi to me is way better. And I repeat, I watched them live and when Maradona went to Napoli I watched a lot of his matches as well.