Anyways, I think focusing on the riserless mobos is better strategy moving forward. Save money on unreliable risers, better heat control and lessen OS compatibility issues.
I love the sound of eliminating risers if possible. Just the time saved troubleshooting the rig if it's acting up would be pretty valuable, even without the additional cost savings. I hope that somebody makes one with ample enough spacing to run a full 6-8 higher wattage GPUs, such as GTX 1080 Ti, Rx Vega etc.
i don't get what citronick is saying about "better heat control" but risers are important to make space between hot gpus, the closer they are together the hotter they get..
quality risers are good, most of my risers from late 2013 are still going strong. and add to that my 775 motherboards circa 2006-2007 that are paired with these risers are still working...
look at that very long motherboard and look at the capacitors in between pcie slots, if only one of them gets cooked you're gonna get some headaches.