Bracket is built on top of Code Mirror. It never feels like a native editor. If Atom is using a Webkit renderer for core editor part, I'm not gonna switch from Sublime anytime soon
Light Table is build on Node-Webkit and it feels pretty good most of the time. (Opening folders is the only spot I've found where it's like, "Wait, something is a little off here.")
My experience with Light Table isn't that fortunate, even moving the cursor through some lines feels sluggish and not great.