vim + screen is all I need to be incredibly productive.
I wouldn't think about having more than one vim running at a time either. It handles multiple files with power and ease. Screen affords me the ability to run commands, tail logs, restart servers, all without my hands ever leaving the keyboard. The combination of the two makes me a faster Perl developer than I ever was. I feel sorry for those locked into the mindset that windows-style editors offer ANY value over vim+screen..