I think Obama did what was needed in order make sure that us as a country would be able to continue to move in the right direction. Not everyone may agree, but I think he is doing his very best. If he did not do something about it than we would not have come to any kind of agreement and we would have been in a lot worse of a place.
He did not stand firm on things that he said he would, and so to my mind he lost some respect. Perhaps that is a form of negotiating, but a president should not say something is not a bargaining option and then bargain about it. However, he did manage to force a resolution to the conflict in such a way that made the GOP back down from their hard line approach and I think paved a way for the future in which the GOP realize it would not hurt to be more reasonable.
President Obama is a great negotiator. He managed to call the GOP's bluff and get everything he wanted without giving up a whole lot. He dug in his heels when he needed to and even used a few intimidation tactics when he needed to. He called enough attention to the fiscal cliff bottlenecks, which were the GOP stall tactics, to make them take appropriate and timely action.
If I am completely honest, I think we needed to address the debt ceiling in the fiscal cliff deal. That was a big mistake. In my view, it doesn't really matter if we escaped the cliff in January. If we kick the can down the road and don't have a resolution in the next month, nothing effective really got accomplished. I think it's great that we broke the stalemate on tax rates for the wealthy but it is just not enough.