I've been using Evil for a couple of months and love it. I switched from Viper+vimpulse and haven't missed a beat. It works really well and was easier to setup. Any VIM user considering Emacs should give it a shot - the best of both worlds, really.
I've been using evil mode and don't really see why you'd even want to move away from the vim bindings. Get the best of both worlds, the nice vim movements and model editing, plus all the nice emacs packages and being able to use elisp instead of vimscript.
It's been pretty difficult as I am a dyed in the wool VIM user. Someone on HN recommended the Evil plugin (http://gitorious.org/evil/pages/Home) for an approximation of VIM movement and other bindings. It surprisingly works pretty well. It's letting me remain productive while I slowly adapt to the emacs key-bindings over time.
I am using emacs-prelude as well (https://github.com/bbatsov/emacs-prelude) which is a startup scripts kit.
I'm still not sold on emacs yet, but I am giving it time.