Well putting aside his absolute nightmare against United, i don't think he is anywhere near as good with the ball as others do. He has a fairly poor touch which has already got him into trouble a few times. His passing seems fairly hit and miss....sometimes good, others poor. He seems fairly indecisive when choosing a team mate to pass to (although this could also be put down to the players not making themselves as available as they could). I don't think he commands his area due to his height. I do think he is a decent keeper but i don't personally think he was worth shipping Hart out for.
It made more sense to at least give Hart the chance to adapt to this system and actually spend the summer recruiting defensive players who can take the ball under pressure and pivot with it to move it pass the first phase of the oppositions press. That's what i would personally have done. For this system to work in the Premier League, you have to have a keeper who is almost flawless with the ball, because the slightest mistake is not only pounced on by the opposition, but also by the crowd (in away games) and that tends to make some of our players shit themselves,