Maxwell is a fielder who bowls and bats a bit. His batting is just T20 style, he has no ability to grind, he will just try and hit out. Against Sri Lanka that might be ok, against India and better nations he will fail. His Bowling is also very average. He doesn't turn it enough, has no other ball but the stock offspinner. Warner (and I don't even like his bowling) is a better second spin option than Maxwell.
Selectors are once again punting on potential rather than picking on proper form. Disgusting, when will they get over this youth fetish?
I've said this before - his first class bowling average is better than Australia's three first choice spinners (Lyon, Beer, Holland) - not saying he's a better bowler than them, but he is a decent bowler. Took 4/40 odd in the last first class game that he played.
He also averages over 40 with the bat in first class cricket.
Not to mention he's a excellent fielder to boot.
I do agree that his style of batting as a T20 player is a bit limited, but then again you can argue that it's the same for Warner.
He's probably not good enough to bat 6, however, his off spin as a third spinner in India could be handy. Samit Patel for England is a lower-order hard hitting batsman and a all round spinner, they're similar in that mould.