Many times I wanted to switch from Sublime Text to Atom, but I always went back for some reason (slowness, not remembering open files upon restart, etc). Maybe this will make me swich for good.
FYI: Sublime Text's plugin API has recently (v. 3118) been updated with some cool new features relating to inline minihtml, which makes something like this more feasible.
While it doesn't currently exist, someone might implement something like this for Sublime Text in the future.
The fact that Atom was free and Open Source is mostly why I switched. You'll be happy to find that it does restore your last session as default now (add in the Project Manager plugin to make switching between projects easier too). Personally I haven't noticed any speed issues but YMMV.
While it doesn't currently exist, someone might implement something like this for Sublime Text in the future.