I prefer GUIs strictly for better window manager and system copy-paste integration, but I think that is irrelevant to vim/Sublime, as you can (and I do) use gVim or MacVim. I like vim movement and editing commands a lot, but I'm not much of a configuration fiddler - I fiddle if I must, but I find no joy in it. I switched to Sublime because it gives me adequate (if somewhat mediocre) vim commands, plus other fiddle-free features that I had to fiddle into my vim, most notably command-t file fuzzy-finding (which also works much better, on top of being fiddle-free). I also really like the command palette (which I haven't seen a vim corollary for) and the package manager (which is much easier than the various alternatives in vim IMO).

edit: For balance, it also has its annoyances, and I sometimes wonder if I should switch back.