Ill start out, im a college student majoring in mechanical engineering starting my third year now.
A few things, a Tablet will be inadequate if you plan on doing engineering... my tablet is 2ghz with 1gb ram and a geforce 6200 with 256mb ram and I find it inadequate for doing real CAD/CAM work.
Secondly, LFS is going to stink, then again my tablet is well over a year old so the newer ones are a bit faster especially with a core 2 duo. But its not going to be as good as a cheaper laptop that has a bigger screen.
Third, I find myself rarely using the tablet features and just using plain old paper and pen in classes.
Fourth, its damned expensive, when I got my tablet it cost me $1700, for $1700 I could have bought a hell of a lot faster laptop.
Fifth, no you won't lose any functionality, XP Tablet PC edition provides everything you need.