As a long time Emacs user, the only way I'd even consider switching off of GNU Emacs would be if there was a port written in Common Lisp that replaced ELisp with Common Lisp. Even then, I'd only switch if it had replacements for the ELisp modules I use (ERC, Slime, C++-mode, etc.).
As an end user, I don't see any advantages in switching to yet another Emacs rewrite in yet another low level language.