From the specs and graph, which I do trust, these are the real deal. My ampeg 8x10 has 4 stock drivers and 4 mod 10's. It sounds really good but, If I actually used the cab to gig with, I would buy 8 of these drivers to drop in right now. Good power handling, great frequency response and yes, they will drop right into an ampeg 8x10 cab. Very cool.
I think that someone could be very happy if they had LDS build them a pair of vertically aligned, sealed 4x10 cabs. Then, cross-fire the pair for better performance. I would love to set my vintage svt on a pair of cabs like that, with the new drivers.