A key consideration to me is startup time. Here's my own observed timings.
Hitatchi 5400, with:
->
Vista (and ~10 programs):
. 79 seconds.
->
XP - fresh (First Restart):
. 45 seconds.
->
XP - Via Chipset/graphics:
. 45 seconds (!)
->
XP - Security (" & Comodo FW & AV and AVG AV):
. 50-55 seconds.
Intel
SSD, with:
->
XP - fresh:
. 33 seconds.
Notes:
-> I measure the time from when I first "Power On" to when desktop first appears.
-> Vista was passworded, so it was PO to PW (password).
-> If a "error" ("Windows did not close properly", etc), I would let the computer load, turn off, and then try again.
-> "Vista <-> XP" wasn't "apples to apples" - I haven't "fully loaded" XP yet on either HDD. Conversely, Vista only went to the password screen, XP all the way to desktop.
Turn off:
->
Vista (fully loaded)
. 30 seconds.
->
XP@5400 (All, inc fresh):
. 12 seconds.
->
XP@SSD:
. 5 Seconds.
I have yet to have a serious play (battery life, Office 2007 "performance", Security suite active, chipset significance, TaskManager@100%), but when I do I hope to report back.