Updates were recently pushed into the Ubuntu 12.10 "Quantal Quetzal" repository for the Unity desktop and Compiz compositing window manager. Performance improvements were talked about, but still there are big problems at hand. The recent Unity/Compiz updates have caused more OpenGL slowdowns, at least for those using Intel's popular open-source driver.
With the recent release of the Unity 6.4 desktop plus a minor update to Compiz, new benchmarks were carried out on Phoronix. Most of the benchmarks in the past few days have been from an Intel "Ivy Bridge" system with the pristine open-source graphics driver support. From this Intel driver testing, these updates don't benefit the OpenGL performance much for the default Ubuntu 12.10 desktop but in some cases introduce performance regressions. The Ivy Bridge system is the CompuLab Intense-PC.
There's other testing being carried out right now from other systems (with different GPUs/drivers) along with comparing all of the latest desktops offered in the Ubuntu Quantal repository (KDE 4.9, LXDE, Xfce 4.10, GNOME Shell 3.5.4, etc). Those results will be published soon while in this article are the Intel Ivy Bridge OpenGL results when comparing Unity 6.2 + Compiz 0.9.8+bzr3319-0ubuntu1 to Unity 6.4 + Compiz 0.9.8.0-0ubuntu1. The new upstream Unity 6.4 release has many changes as outlined in the change-log. The Compiz update (and its change-log) pull in the new code that allows Compiz to work on OpenGL ES plus other work on the struggling window manager.
Unity/Compiz is still struggling with performance even after they've already made significant performance improvements there is still room left for improvement, even for 2D performance. Canonical recently announced they would be killing off Unity 2D and this is still the case for Ubuntu 12.10, even though many Ubuntu users prefer Unity 2D and it does perform better without using Compiz, a compositing window manager.
So here are the benchmarks of Unity 6.2 vs. Unity 6.4 with the updated Compiz packages. The comparison against other Ubuntu 12.10 desktop options will be published in another Phoronix article in a few days, but as indicated already -- Xfce 4.10 is still much faster than Ubuntu's Unity. KDE -- even when not suspending its compositing effects for full-screen windows -- still also has a number of advantages over the default Ubuntu 12.10 desktop.