Honestly, at this point the only things actually keeping me using ST over Atom are (1) the SFTP plugin, (2) per-project settings, and (3) click-and-drag multiple cursors... and Atom plugins have already started making headway on 1 and 2.
I've came to like it while pondering dropping 70$ on ST when i got Chocolat for free in some kind of software bundle (can't recall which), so there's that..
I believe Atom will run laps around ST before 4 development is even started.