There has been quite a lot of discussion about them over on TGP. One particular acoustics and cabinet design expert has poo-poo'ed the designs, and pointed out big potential problem areas with them. The chap who has criticised them does seem to be a genuine expert in these matters, and has convinced me about it.
From what I remember the CCC designer himself admitted that there was very little science going into the designs, just a lot of experimentation , and listening to see what sounds OK. Apart from that, they produce a nice looking finished product, and seem to market them reasonably.