I don't really understand the comment about etags; if you use ctags in Vim, you'll get the same kind of functionality. If you want something more advanced, Emacs has support for cscope and GNU Global which give you more features. Considering that he's interested in having something better than VimScript and wants org-mode, it seems that Emacs + Evil would really be the best fit for him.
I had this same problem: they function differently in evil mode than Emacs mode; for some reason evil does its own word boundary definitions for etags lookups, and it breaks up words on underscores. I dug into it, and it was some problem with evil's word semantics (that only existed for etags lookups). I ran out of energy to debug it further, and just went back to Vim.
Regular etags called with the emacs bindings worked just fine, but switching contexts from evil mode was a pain.
Thanks for quantifying it for me. I never dug in deep enough to figure it out. It always just felt "wonky" when I used. (That's an opinion, of course.)
Could you mention this on the mailing list? I don't know if I'll have time to fix it any time soon, but someone else might, and that needs to be fixed.
