I'd say files up to 100MB work reasonably well, but when getting to the 500MB/1GB range, I need bust out a more performant editor, especially for find/replace.

I'd say files up to 100MB work reasonably well, but when getting to the 500MB/1GB range, I need bust out a more performant editor, especially for find/replace. This is one of my main problems with this otherwise excellent editor.