I am getting ready for my next build: waiting for the improved skylakes at the end of October, and hoping there will be more than one board that provides integral Thunderbolt 3 connections. I would really like to see a review on the Gigabyte Z170X-UD5 TH. Which is the only MB that has it at present. I gather that Asus is going to offer an expansion card with it, but not with an intel chip. I guess I would consider a board and a Thunderbolt 3 expansion card if everything else was right, depending on the brand and speed of the chip on the card.
I am kind of surprised at the lack of interest in Thunderbolt 3. I move files of ten or more GB to external storage all the time, but beyond the unparalleled speed, the one connector to rule them all idea is great. My next board, gotta have it, along with USB 3b or whatever is the latest. Couldn't care less about SATA Express.
I am almost tempted to build another notebook and connect it to external video cards -- almost. Now if someone would just dump a bunch of the latest MSI whitebooks on ebay it would be a definite maybe, but only if they had a Thunderbolt 3 connection. At this point I would not even consider a notebook without it, and my guess is that when people realize the potential it provides they will wish they had it. Maybe I am just a victim of hype, but in this case I kind of doubt it.