If you've used swap all the time since January, how would you know if it makes a difference? (I'm just curious - maybe you stop swap now and then?)

The N800 has enough RAM or it wouldn't work (programs would get killed). However, the Linux kernel will use any free memory for disk buffers, that's where the only improvement could come from. But on the other hand it shouldn't push any application data to swap only because it could use RAM as disk cache - disk cache is the lowest priority usage for RAM in the sense that it's the first to get taken if an application needs memory (it won't start pushing other data to swap and leaving disk cache alone). There are some other rare circumstances that could push data to swap. Because of all this I hope you'll understand that I'm somewhat sceptic to claims about improved performance - I'm not saying it isn't true, I simply would like to see some hard numbers..