Vista can be run on anything, almost. It just depends on what you take out. You should know that if you're "super-geeky" shouldn't you?
To the OP: I think what you're referring to are the SSD versions of the AspireOne. SSD stands for
Solid-State Drive. While I myself do not know much about SSDs, because I always prefer space to..."shock-resistance", I believe I've read that SSDs' read speeds are faster, but their write speeds are slower than traditional hard drives. And since XP is constantly writing crap all over the drive, the hard drive would be a better choice.
Basically,
SSD:
Pros:
- Shock-resistant
- Fast read speeds
- Slightly lighter (barely noticeable difference)
Cons:
- Slower than hard drive in XP
- Very limited amount of space
- Last only ~3 - 4 years
- Replacing them is expensive (this should change in the future, though)
Hard Drive:
Pros:
-Fast read/write speeds for XP and Linux
-Plenty of space
-Cheap, and easily upgradable
-AspireOne chassis (or casing) is slightly bigger (kind of a side effect, may prove useful for those who wish to squeeze millions of mods into their AspireOnes.

)
-Will last long, if taken care of (I have an old 20GB IDE HDD from 1999, it still works great)
Cons:
-Not shock-resistant, too large a bump will damage it
-May use slightly more battery (haven't seen any proof though)
-May produce more heat (also haven't seen proof)
So, to me, the hard drive is better than the SSD version. However, if you are a professional photographer or something, and go up mountains to take pictures, and want to edit on the spot, an SSD would be the way to go. But I'm not.

So, I'm going with the HDD.
Hope this helps!