We’ve been able get the UGA-2K-A running on Ubuntu 12.10 doing a similar process. All that is missing is a kernel newer than 3.5, and then DisplayLink devices are mostly plug-and-play under Linux.
This is my recommended source for pre-compiled kernels for Ubuntu. http://kernel.ubuntu.com/~kernel-ppa/…
I wouldn’t recommend the Xorg-edgers PPA, simply because it’s known to be very unstable, and it’s not necessary to get things working.
Regarding the WM crash, I can’t say I’ve ran into that issue yet. It may be XFCE related.
Performance-wise, it varies depending on your CPU and WM. The performance should be good under any non-compositing WM, however.
The only reason we haven’t made a blog post regarding this is that installing a non-standard kernel for your distro can cause several issues and just generally not recommended for end-users.
Let me know if that helps or if you have any other questions!
Although it would have been of great help if info about the kernel version was on a blogpost from the start. It is already staded on the plugable page that linux support is only for experienced linux users, so there should not be any reason for not posting that “vital” information officaly, IMHO.