While my Eee is perfectly adequate to most of the things I do with it, there are times when its slowness starts to really bug me, particularly when I'm using it as my main computer, such as when travelling. To a large extent the "low power" thing is intentional and by design: it's what makes it possible for the netbook to be small and light yet still have a long battery life and run cool without fans. You're not supposed to be running six applications on it, and even when I'm travelling, I try not to. But it can get laggy even doing a few things.
A lot of that isn't due to processing power but due to disk swapping, and that in turn is largely caused by the rotten way they've set up the two solid-state hard drives. Instead of one 12G drive, there's a primary 4G partition on which Windows lives, and a faster 8G partition for data. This ends up being kind of backwards. Even after you do everything possible to move stuff onto the second drive, the 4G drive is barely enough to keep up with Windows itself, and often runs out of space and needs to be pruned. Unfortunately, that's where swap space also lives, which means it lives on a small, crowded, slow drive.
Generally speaking, one of the best ways to improve a computer's responsiveness and speed is always upgrading RAM. Most computers ship with less than they can benefit from, and RAM is cheap and easy to upgrade. That's even more so when swap space is slow and scarce. So it should have been an obvious thing to try, but strangely it didn't occur to me. I never even looked into whether it was possible. But it turns out it's not even difficult or expensive.
It only takes two screws to open the panel on the back, then the old 1G card pops out with two clips and the new one pops right in. Simple as that. The 2G cards only cost $45.
So far the computer has been a lot more responsive. It's not so much that it does any particular thing faster, as that it doesn't grind to a stop and become unresponsive for ten seconds every so often. Even when I do a few other things at the same time it comes out pretty good.
So I don't intend to look at upgrading anymore. My Eee will be fine for a while yet to come.