Thank you for this news. I haven't been able to find a review of the Z170X-UD5 TH anywhere for weeks. Now I can look up these other board's reviews and see if they are worthy of my next build.
I would really like to see a review of one or all of these boards. Theoretically that is all that is keeping me from buying one. Asus will be using their own chip from a subsidy to deliver TB3 -- first as an add-on card I believe. And then their is this
ASUS Z170-Premium to contain Thunderbolt 3 and a U.2 port
http://www.overclock3d.net/articles/cpu_mainboard/asus_z170-premium_to_contain_thunderbolt_3_and_a_u_2_port/1
Some of those notebooks with TB 3 are already for sale.
And of course the big push to finally allow docking of laptops to some serious GPU power via TB3 without all the fuss that is now involved in rigging your own eGPU setup. I have also seen some little external TB3 devices coming out for laptops. At this point I wouldn't purchase either a laptop or a motherboard without it, even if it is in the form of a card or external enclosure.
I guess TB3 could run two 4k displays in a VR HUD, if anyone would care to build one for me. Can you imagine the pixel density.