http://www.positive-feedback.com/Issue11/ces04dg1.htm
This was quite a while ago, and I suspect much of the description as being a touch of snake-oil... (thinking of the liberally-sprinkled "golden-ratio" references)
However, about 7 years ago, he DID produce an eliptical capsule, which DOES actually sound good.
You should look into it... It's used in the Bock 507; essentially a recreated U47 with an edge-terminated elipse capsule replacing the M7/KK47.