I think the benefit is exactly the keybindings. And the fact that it is non-modal. It works like a text field in a desktop GUI, there is almost no state. You can't mess the state up. Contrast it to vim, where I got into the habbit of bashing ESC three times to be sure I'm not in a mode. Or emacs, which is nice until it's abstractions leak, and you accidentially start editing a configurations pane or something.
I am a part time vim user, and generally like it, but sometimes I find the mental load of the key bindings too high. Anything more complex than d, and I have to stop a moment and think about it. In that time, I can just hit the cursor keys (and Home, PgDn, ...) a couple of times.
It's a trade-off: Do I use a bit of mental power, and save some finger movement? Then I go for the vi way. Or do I use less mental power, and delegate tasks to my fingers and eyes to do autonomically? Then I go for the sublime / notepad / VS way. I might press the arrow key a couple of times, overshoot, go back, ... it may look inefficient, but it's not slower, just a different use of resources.
I've been looking for a Sublime style editor for the terminal for ages. Actually, way before sublime, I've been looking for an edit.com style editor - Nano is one thing, but I want one that respects CUI-like conventions. Shift for selecting, CTRL+C for copy, .... I will definitely check this out.