Depends on your PC system, and graphic card.
Also the game itself is typical interface based so a PC is nice for that..
Also you will miss all the wonderous little plugins and the add ons that people do!
I was a bit tired of all the walking around and downloaded a plugin that increased the walking speed with 25% for everything in the game. no more daydreamers
And what you talking about not being able to tweak the PC version???
The Sb cards have special plugins for the game making the music, and yes the official extra soundplugin sounds like a plugin to me. NAd my GeForce 4 card can take full live shadows and everything. I would say I can tweak more than you!
But as mentioned above. If you have an older PC and not interested in making to much of your own additions to the game, go for X-box version. If you have a preffty new PC with a GeForce 3 card.. Get the PC version!