Most people have never heard of the "Punch" Subwoofers also from RF. Ive run kickers for quite some time now...and liked em. But there are some better choices out there now.
Kicker L7's aren't shabby.. JL W7's rawk. Really, if you're going for the average sub price, they'll all pretty much do. Never had a problem with JL Kicker, Polk, Ztant, Orion (do they even make subs anymore?) Pheonix Gold, MTX, Or Rockford Fosgate. I've ran them all. My Fav's were Orions, followed by JLAudio, then MTX
I had 4 10" MTX Thunder 6000's with a 1000 block D series monoblock by crossfire in a shadow es turbo.. omg that was loud. i was running .5 ohms... that's probably why i'm deaf now.