Well, I saw a video once, showing Mandrake running on the XBOX, and it booted FAST, and opened programs REALLY fast! But my install takes about 30 to 40 seconds to boot, perhaps longer I have not timed it exactly.
Then when it runs it takes about 3 or 4 seconds for a directory to open up, and a little longer for Mozilla or something, nothing like the video I saw. But then again if I could learn to disable all those unwanted processes at start up, that might help things out a lot.
As for games...
Well my friend said he ran Duke 3D under wine and it ran great, I was gonna test it under VMWare but have not yet. DOOM Legacy and ZDOOM run great, a HELL of a lot faster than they did in a standard install of Redhat on a computer I had that was a little aboce the XBOX's specs.
Hope that helps you some.