Acer use to be a pretty good notebook but they just are not reliable these days, to many come back for repair. Lenovo is the old IBM Thinkpad there is a reason they are Lenovo now. Yes you can find a cheap Intel but trust me, I know you won't, you'll get burned. The new Centrino's just don't perform I have three, actually two now one crapped out due to a bad MB, and the P3 actually runs faster then the DuoCore Centrino's.
I work on this stuff every day and provide support for customers and businesses all over the US and Canada so I see a lot of product and their faults. When it comes to notebooks there really isn't one that is just great they all have some issues. HP and Toshiba seem to be a bit better then the rest but Sony and Asus are also pretty good just too expensive for what you get.
Vista is a bugger you're right on that, but if you turn off UAC, the firewall, and disable Windows Defender in the Services it's not to bad but there are still some issues you could run into. I've talked extensively with the MS rep and you might as well hit your head against the wall they just won't get it. You can still get drivers for most of the new notebooks for XP so you could buy one and install XP on it. Circuit City is a pretty good place to go and even Worst Buy has deals from time-to-time you could also look at Sam's or Costco as they have deals too.
For Mike; If your running a quadcore you must run Vista or 2003 as XP will only utilize 2 cores. Also it's not like you have a choice on what core runs what, software has to be written toward multiple cores to use multiple core and so far OS load balancing isn't perfect.