How big is your project that you find atom slow? I have gone back and forth between atom and sublime 10 times in the last 10 minutes and I have not found a single reason why anyone would notice a lag in a project of just a shade over 10,000 files. The difference in speed is completely imperceptible.
Not saying I love atom more than any other editor (I typically use terminal vim) but in my experience over the last week, any complaints about atom's sluggishness seems either outdated or wrong to the point of absurdity.