JetBrains has granted us a group FLOSS license for PyCharm: http://www.jetbrains.com/pycharm/ . It's good for a year for non-commercial use. If you would like a copy of the license just email me and I will send it to you.
As for how it is, I have not used it yet, but Richard Jones can't stop raving about it (and he's a Vim user! =).