They are using wonderful Audax Aerogel's which list for $81 each. assuming they can get them for 40 each in large quantities, and they are using 30 of them total, that's just $1200 for the mids.
They will be OK in Comb distortion if they cross them no higher than 2500hz. Lets assume that they do.
The problem is the SEAS Prestige 27TFFNC/G(31 bucks each at retail). These are 2.08 inches apart bumper to bumper. If they were able to make them only .80 inches apart then comb filter distortion would start at 17Khz, but at 2 inches it starts at about 6600 hz. This is clearly audible.
Why they would do this when they could simply buy a set of B & O ribbons and not have the issue is beyond me.
If you put my system or one of Rick Craig's system next to it and listened to the upper range you would clearly hear a difference in lack of air. Listening by themselves will probably be overwhelming with those fabulous aerogels.
They can do what they want, but unless Dr Griffin really fudged his research for some reason, I'm not suggesting in any way that this is true, and actually agree with him 100%, these people are ripping you off because they don't want to spring for a tweeter at the same price range as the mid range they are putting in.