Just to clarify, does emacs/magit really pop up when you run "git rebase -i" on the command line? I haven't experienced this, but maybe that's because my EDITOR env var is set to "vim". I would find that very annoying.

I like magit, but I never figured out the rebase flow with it, so I just do that on the command line.

Where magit really shines for me is being able to stage and unstage hunks of code very easily. Looking at my current changes, stashing and un-stashing, searching through git log, seeing the diff of a particular commit, quickly fetching from upstream or switching branches... All of that becomes quick and easy once the key bindings become second nature. There are definitely major quirks of the UI / UX, but I found it worth fighting through that.

edit: I've re-read your post again, and I would just like to reiterate that staying away from magit's interactive rebase might be a good idea. Besides that, I also try to stay away from triggering ediff mode -- even after spending time with it and getting to know how it works, I've decided that it's simply not very good.