While it looks like the overlapping seams might add strength/rigidity in a favorable way, i can't help but think that the lack of uniformity in the cone's density would adversely affect it at higher frequencies.

How much room for improvement is there with 515 cones?

At the entry fee i suspect those are well past the point of diminishing returns for the typical Altec enthusiast.

All that said, i'd like to spend some time comparing them to originals.