Aside from tansparency, I don't think there is anything (for LS, anyway). Stability will be there, and multitasking is smoother in NT (Win2k = NT 5.0, XP = NT 5.1).

My advice on any new PC:
Athlon XP: good.
Athlon64: very good.
Pentium 4A: OK.
Pentium 4B: good.
Pentium 4C: very good.
Pentium 4E: very good.
Pentium 4 Celeron: avoid like the plague. A Celeron 2.6GHz is about even with a 1.4GHz Athlon or 1.6GHz P4.
Windows2000 and XP like RAM. 256 is a minimum for actual use, and if you multitask a lot, 512MB will do very well.