One of my friend used to have a Wrangler with 4 MTX Thunder 7000's. With a Fusion 1000 amp. That insane. Then he went to some Fusion Powerplants. That was even more then the 7k's.
Well, I believe the BTL has less linear XMAX, but more Xmech than the BL, would make sense since a larger linear XMAX is generally for SQ, where a smaller linear xmax with more Xmech is more for SPL.