install XP then answer your own question. Stock, Xp is unbearable slow, with all the tweaks, it's still slow.
On Vista, things install pretty slow, even things that are less than 20MB, (messenger, itunes, origami), so AutoCAD wil surely take hours to install.
My One still has the stock SSD, and after I upgrade (My 80GB ZIF drive should arirve on Tuesday), I might try installing it, because I start an Autommotive Engineering degree in spetember (Pending A-Level results) and it would be great to have it in such a portable form.
Rory