I did the same thing, but a few things to ask. Did you turn off indexing on the HD? Ever since the Windows update mine has been the best! I don't even use my tower or TC1100. I just installed OneNote and am very pleased with this device. I hope everyones Q1U-Vista works as well as mine.
I found a program you can use to overclock the CPU too 998-1000 GHZ Do a search and you should be able to find the program here on the forums.
Sometimes mine just sits there and gets stuck too, but I think its a vista thing, doing something in the background. I give it a few seconds and it catches up with itself.
Since the Windows update, my device is really fast and responsive. I hope everyone is having the same affect as mine. Even writing this 'the cursive "rarely" lags, but it quickly catches up with itself.
I am still pleased with this device and will use & keep it for awhile and wait to see what becomes of Atom, AMD and c7-M processors and battery life before I commit to another UMPC. I hope this may help in some way. I am keeping an eye on the M528 and the Everrun Note. Lets see how battery life improves as well assize. 7" screen is perfect for my eyes; but pocketability is what I am interested in too.
I have noticed over the past 7or8 months that the windows updates have improved my beloved Q1U even the wifi and the Atheros card are behaving very well. Sorry so long winded. Good Luck!