They are pretty awesome, but one would have to try out all the popular brands to really know if they are the best. The only brand I have read many comparing to these are the Fosgate T1S series. On this site, some have said that the Dayton Audio LS12-44 sounds just as good for half the money. So it is all subjective and I myself am partial to JL Audio.
I can say that Kicker’s L7T subs are pretty solid shallow mount subwoofers. I have had a 10” and 12” in my trucks, with both being able to handle more than rated power.