get the centrino, battery life almost double that of a p4 and performance should be on par. my sister has an X1000 and i've been using my friends P4 2.4 Dell 4150, the x1000 only has 256mb of ram and the dell has 512 but the x1000 definitely performs better. plus we get a lot life out of it. then again, w/o an a/c adapter plugged into the p4, it only runs at 1.8ghz or something like that.