Check at
http://www.digigram.com/products/getinfo.htm?prod_key=9000 for more specifics on connections. They don't really outline processor requirements, unfortunately; but my laptop has a 1.7G P4 w/ 512K memory.
I've used the laptop equipped with the VXpocket V2 to record live a few times times, just to experiment. I've had good results with it (km140s>mp2>VXPocket V2>Soundforge 6.0>Inspiron 8200 as well as SBD>VXpocket V2>laptop setup). The only 'stability' issue I had was initially getting the Win XP driver to work. That was a pain! Also, at one show, the headphone out stopped working mid-show. I'm not sure what caused that; but I suspect it was an issue with the laptop itself (some freakish thing that happens with the particular model Dell I have...aren't I lucky).
The other thing that can be a bother is the breakout cable itself. It can be unwieldy and if you're not careful, it can disconnect from the card during the heat of the moment. Fortunately, this has only happened to me during a soundcheck.
Still, budget-wise, it was a good deal. I know I'm gonna hear groans from some quarters; but I only paid $99 plus shipping for mine (new, in-box yet). Except for the items I listed above, it's worked just fine. No lock-ups, freezes or diginoise experienced thusfar. Digitally, it's been very stable.
Hope that helps!