[rgiar]

In a word, emacs is responsive -- you realize this as you slowly become familiar with the basic components: buffers and files, the point and region, keymaps, ediff, ffap, running shells inside emacs, tramp, etc. and then, yes, finally emacs lisp. Using these basic tools, you can mix, match and customize until it does what you need for today's project, no matter what language or OS,however many files, script languages, build tools, etc.

At some point it becomes clear that emacs is actually a programming environment for text editing with emacs lisp in the position of universal configuration, scripting and compute language. If you can think of something you want to do with text,files or code (albeit limited to an ascii interface) you can either find it in the extension community or you can quickly bend emacs to do what you want.

My learning curve was approximately two years to feel very competent, five or so to feel like a power user, and then 8 or so to feel make it do most anything.