I haven't actually abandoned sublime text 2... for the time being i've been using vintage mode as you suggested. I've went cold turkey with MacVim for weekend projects but I still use sublime with vintage for work. If I do reach that tipping point where straight Vim is easier/faster/nicer then I would jump ship.
I switched from pico/emacs/TextMate/Notepad++ to VIM about three years ago. I always hated vi. I love it now, and really wish I would have switched earlier. But the advantages don't become obvious until you make yourself to live with it for a while. The initial learning curve is pretty steep, but once you get over that hump it's pretty easy going.
This is very different from emacs, which was very easy for me to do simple tasks but very hard for me to do anything complicated. It's also different from pico, TextMate, and Notepad++, which are easy to pick up but plateau, sometimes leaving to write a script to do what you need.
Using a vi-like mode for another editor doesn't really cut it, not unlike an emacs-workalike that isn't built atop a powerful scripting language. For me, it's about the way commands stack and compose rather than using hjkl instead of arrow keys.
Good luck and have fun!