I went to watch "This is it!" yesterday and I must say I was not disappointed. OK, the movie has probably been edited to show the "best" of MJ, but what comes across is that he is a very talented and professional artist and musician, and a genuinely nice guy.
Despite having numerous assistants and directors to help him with everything, MJ is clearly in charge and tells his people what he would like to change and improve. Furthermore, having his track-record and success he could have become lazy but instead he wants things differently all the time, saying "this is why we have rehearsals".
He also appears to be very nice and patient with everybody, a bit too soft for me (saying "I love you" and "God bless you" every two minutes) but watching this still I was convinced that he was a good person.
Go and watch it if you can.