User blog comment:Selim 009/Seven Dragons Vs. Seven Dragon Slayers/@comment-14885023-20130428194154/@comment-7418318-20130428195222

We never saw a Dragon Slayer use Dragon Force against a God Slayer.

Considering the massive powerboost that Dragon Force gives I'd estimate that Dragon Slayers are the stronger ones, if they can pull all their tricks out, unless God Slayers have some equivalent that we simply havn't seen yet.

Also consider Orga and Jura for a moment. Jura finished Orga off very easily, but was then defeated by Laxus (who's "only" 2nd generation to boot). Later the same Jura that totally owned that God Slayer wasn't able to so much as scratch a Dragon.