Been testing it out the beta, in my experience performance is better but still behind tslint, though tslint lacks a ton of rules compared to eslint so I am guessing that is partially why. I think the webstorm struggle is a webstorm specific issue, I've seen a few of my co-workers experience similar webstorm slow downs from eslint (and ts) but it works fine for me in vim without any slowdown of the editor itself.