As described by the other commentator, this isn't quite the same. My normal workflow is 2 command line windows and ~3-4 open files. Doing this in tmux while trying to maintain the ability to move and split windows at will means that's 3-4 instances of vim. Not a great experience if I want to save all. Also, moving windows in tmux/screen has, for me, always been a huge pain of remembering a bunch of keyboard shortcuts. In acme I just click and drag stuff.