I'm using ESLint for all my projects for the last year.
I find it much easier to customize ( you can write your own rules )
And because it uses the Esprima parser, it's easier to integrate other things like JSX or ES6.
"ESLint is slower than JSHint, usually 2-3x slower on a single file. This is because ESLint uses Espree to construct an AST before it can evaluate your code whereas JSHint evaluates your code as it's being parsed. The speed is also based on the number of rules you enable; the more rules you enable, the slower the process.
Despite being slower, we believe that ESLint is fast enough to replace JSHint without causing significant pain."
I do javascript full stack and use eslint + vim for many hours/day. I don't notice the slowness. It may be one of those benchmarks that doesn't translate to real world productivity. Eslint has more rules than JSHint, easier to configure (errors display the rule name) and more accurate.
Oh, I see, thanks for pointing it out.
Still, speed is not such an important factor for using a linter.
I prefer being able to have custom rules and up-to-date stuff like ES6 and JSX.
Check out an older intro by Zakas http://www.nczonline.net/blog/2013/07/16/introducing-eslint/
( Also I think it's a bit faster than JSHint/JSLint ).