Sigma/Coppergate's Vapourware HomePlug AV chip performs better than real chips

Sigma is promoting "ClearPath Technology" to solve the noise problem powerline technology is open to. It is based on Sigma's MIMO implementation for HomePlug AV. Mike does a great demo video, but does not explain that he is afraid to send their chip to HomePlug's Interop Plugfest. Why is Mike so worried.