I'm gonna ignore the steve meade part and answer the underlying question here, are BTL's louder than MT's.
The standard 2 slug BTL is as loud as a MT itself
The more options you add you can make the sub louder, or queiter.
For instance adding cooling reduces motor strength but adds more thermal handing. On the other side of things tightening up the gap, for an SPL application will increase BL which in theory could make the sub louder. So in conclusion i dont know if he gained or not, but im sure it handles the power better now.