The thing is, a lot of computer games and whatnot don't exceed using 800 megs of RAM. I think Hellgate: London didn't even take a lot of RAM, but still ran choppily on my high end laptop.
What you may end up having to do if you want more speed is overclock it a bit.
http://www.gatzet.com/overclock-asus-ee ... 1000h.html That and SetFSB work, from what I've read.
Adding more RAM when it's not necessary can also be a drain on the battery, not much of one, maybe take about twenty minutes of life or so, but depending on it's speed.
Anyways, run some tests, do some benchmarks, tell us what happens. :3