weberdarren97 :
I wouldn't go all the way down to H110.
Both H170 and Z170 have a PCIe x16 link between the primary PCIe connector and the CPU, so that's not a deciding factor. However, Z170 allows for 20 additional lanes while H170 only allows for 16. However, that mean that both could support three-way SLI or Crossfire with all cards running at x16. With H170 could have three way SLI or Crossfire with the third card running at x8 and then have a sound card and USB/Firewire/Ethernet card as well. With Z170, you could have three way SLI or Crossfire with all three cards running at x16 and then have sound card and USB/Firewire/Ethernet card as well.
SLI only works with direct PCIe lanes, not through the chipset. Also, only Z170 allows splitting direct PCIe lanes (rather than just have a single x16 link). So you can't SLI at all on an H170 board, and you can only have up to 2x SLI on Z170 (and even then, not all Z170 boards support this). Crossfire requirements are more lax, but if you find a board that supports crossfire and not SLI, I'm pretty sure that means the 2nd card in crossfire is using a x4 PCIe connection through the chipset, which will have a performance hit.
Basically, if you want a multi-GPU set up, get a Z170 mobo that supports x8/x8 PCIe. If not, there's nothing wrong with getting a H110 mobo, as long as it has all the connectors you want.