I browsed the Minireader Site (thanks for the link somewhere in this forum!), and found a very comprehensible speed test of our N800 along with a Pepper Pad 3, Archos 704 WiFi, Sony mylo, Apple iPhone, and Archos 604 WiFi.
No, the N800 didn't win. It came (edit: mostly) second to ... a x86 CPU
I had the misfortune of buying a Samsung Q1 (1Ghz Pentium M model/1Gb ram) before I picked up my Nokia N800. Even though it is faster than the N800 at some things, it's lousy because it's way too big an heavy (particularly because the screen resolution is the same as the N800), and the battery life is a joke (and a bad one at that).
I use the N800 a lot more. Even with the somewhat choppy youtube performance, I'd rather use the N800 to watch video online.
The biggest problem with the UMPCs is that Windows XP wasn't designed with a touch screen user interface in mind. Even though the screen resolution is the same, you can't use the Q1 without a stylus, because the widgetry of Windows XP is too small. The N800 is a marvel of handheld design. Apple could learn a thing or two about touch screen design from Nokia, IMO.
Imagine if MS would get off its duff and design a touch screen widget set for windows, it'd be swell, to be sure.
The only reason I'd buy a UMPC is to wipe XP off it and install a Linux distro.
I'm thinking dual-boot with Ubuntu full for work when at a desk and electrical outlet and something less intensive and touch-screen optimized for on-the-go stuff.
But I don't know if the hardware driver support is there for a full-blown Linux distro on a UMPC.