So what's the best cost/performance effective option for those of us with several GPUs sitting on motherboards such as the ASUS B250 which has 18 pci-e x1 slots?  Will there be some standard go-to motherboard?  I would like that very much and don't mind paying for it as long as it fits in with performance/cost considerations.

And... I've completed some survey but I don't know how accurately anyone could realistically hope to evaluate such surveys given that the consumers completing the survey still do not have accurate performance statistics or proof of concept.

I'm ready to purchase as many as would be feasible for a 14 GPU rig and perhaps more later but that all depends on performance and trust.