Let's list out some of my favorite features of Sublime Text (please keep in mind I switched FROM vim to Sublime):
1.) VIntage mode that allows for 99% of day-to-day vim stuff 2.) A plugin system that uses Python and offers a full-featured API (vimscript anyone? pfft) 3.) Full mouse/windows support (i.e. it's not ghetto mouse support thrown over a terminal window from the '70s) 4.) Textmate-style themes that even allows tweaking to the UI 5.) Native Linux, MacOS, and Windows versions
The only negative is that it isn't open-source, which I hate, but the licensing is very reasonable (it's per person, not machine, so you can install it on as many devices as you use)
I'd really like to see you give a real-world example of how it's slow compared to vim/emacs, because maybe I'm missing something. I've been using Sublime Text for over a year and have only had to break out vim a couple of times for some crazy vim-style search/replacing or to quickly open some super-large text files (I think better large-file handling is in the works for sublime though...).
Oh, and one of Sublime Text's best feature? It doesn't come with the elitist attitude that a lot of vim and emacs users seem to get... :)