I don't think the problems are so much with Ubuntu, as with the present state of the Linux client, and it's probably the fact that Ubuntu has a large user base at present, especially with new users, and lets face it, Linux isn't the most user-friendly OS for running anything as demanding on the user as Planeshift.
Many problems are related to drivers, and as a long time Linux user, I know that drivers can be difficult to get running, anyone who has tried to upgrade or update a kernel driver will tell you that it can descend into dependency hell pretty damn fast, to say nothing of requiring the kernel source, matching compiler and tools, and sometimes a broken kernel is all you end up with.
So unless someone knows of a distro that has the latest drivers, is easy to update/upgrade, comes with full kernel sources, is in active and has a good user support community behind it, i'll be sticking with my own personal favourite, it's not Ubuntu, or any of it's other flavours, it's slackware based, and it's not really new user friendly, but i'm used to it...... Now all I have to do is install an Nvidia driver based on an older kernel version that I don't have distro kernelsource for...........
