I think I'm the one from the other thread who mentioned lag on USB keyboards. It would definitely be great to add this to bugzilla, as I would love to have this issue fixed. It is currently my main gripe, now that my other main gripe is figured out. I just had another idea that could give us some insight. This post describes hildon-input-method, which eats a lot of CPU when typing, and it mentions how this could probably be gotten rid of if you were using another WM. Does anyone use KDE on their n810? Have you tried using the USB keyboard through KDE? I haven't gotten advanced enough to install something like KDE, but that might give us a hint.