I don't notice typing lag, anymore. Just now I opened it up and tried to get ahead of it by slamming flat hands on keyboard, but it kept up fine.

My current performance complaints are: startup time, big files (especially big files with highlighting), selecting large blocks of text (spanning more than a screen), and probably some other things I can't think of right now. Some of the plugins are buggy and prone to screwing up more than just the thing they're supposed to changing, but that's not performance-related. Just immature code that's expected of new-ish projects.