Yeah, barely 1.3 kb minified if you're using it on the client side. It's also compatible with JQuery deferred's.
Only if you consider that it is compatible to miss P.Deferred(), P.promise(), P.when(), parole.state(), parole.progress(), parole.done(), parole.fail() and parole.always()
I tend to know about that because I am currently writing a lib that is going to be both Q and jQuery compatible: https://github.com/JeanHuguesRobert/l8/wiki/ParoleReference