Yeah, if it's a NEW Purchase, then might as well get Godzilla or one of his buddies.
But if it's something they already own, I prefer to save them money and go the SENSIBLE route and tell them that
if it sounds good, then it is good, regardless of the kind of subs anyone else has.
BTW, I have 10 subs = Six of the RBH dual-10" subs plus Four of the Velodyne 12" subs.