I have been using Ubuntu as my main OS for 3 cycles now, with a Radeon HD 4870 video card. In every cycle the open source video drivers were not enough, meaning that something was not working right. Weather it was the movies or Unity 3D (compiz cube in the old days) I always had something which was not working. So I always installed the ATI proprietary drivers, thus solving the issues.
Precise was the first OS upgrade I have ever made (for the old ones I always made a complete new install). So, before upgrade, I have uninstalled the ATI drivers and reverted to the open source one in order to avoid issues.
After the upgrade everything is working as it should with the open source drivers Gallium 0.4. I have all the nice 3D features and full HD movies are running.
So, I am really asking myself, if there would be any reason for me to turn back to the propriety drivers from ATI? I mean do you guys know for sure there are some features present that are not in the open source one drivers?