I've been using emacs since the mid 80s, initially on an actual lisp machine. For a long time, I just used it out-of-the-box without a lot of extensions, but lately I'm really liking some of the extensions like "org mode" and C/C++ support. Emacs goes well with my mechanical keyboard (HHKB). :-) I've almost forgotten my command line git because I use "magit" in emacs all the time.
Emacs and its various extensions are really good at dealing with information represented in text form. That's a philosophical commitment more than anything else, and it's incompatible with proprietary file formats and things like IDEs.
IMO, emacs has a huge learning curve and I've never actually recommended it to anyone else. However, I couldn't live without it. People that could benefit from emacs usually find it on their own.