I voted that "I don't know". He definitely did some things that if done today would seem downright horrible. But who are we to judge this man from the 7th Century? What do we know about what it was really like in that era? With hindsight we can see that his movement turned into something massive and terrible. But maybe he never imagined that would happen. Perhaps he was just trying to reform a few things in the Pagan society a little bit and knew no one would listen to him if he didn't claim to have divine backing, then he just got carried away with all the power, or maybe he was generally insane and plagued by nightmares about judgement day.
Most of the hadiths paint Muhammad as kind of a bad guy in my eyes, but look at this one:
....Abu Dhubab reported the Messenger of Allah as saying:
Do not beat Allah's handmaidens, but when Umar came to the Messenger of Allah and said: Women have become emboldened towards their husbands, he (the Prophet) gave permission to beat them.
http://sunnah.com/abudawud/12/101Who knows if this is authentic. But if it is, I get the feeling that Muhammad was generally trying to make some nice laws (don't beat your wives guys). But he was limited by enormous political pressures. How can you keep an unruly band of warriors and caravan bandits happy and loyal by meddling in their private lives and telling them how to treat their wives? The answer is you can't. Nobody could. None of us could, if any of us stood firm and refused to back down on the wife beating rule then we never would have been able to lead these thugs for long enough to conquer Arabia.
He was a man of his time and he could only get away with a certain amount in the violent society in which he was born. I certainly would not have done things the way he did it. But I would probably have never rose to such power in the first place.