The XP-SLI is ok if your budget dictates a slightly cheaper board. Seems that board overclocks ok, but has fewer power phases than boards slightly more expensive, and doesn't have the greatest UEFI BIOS, lacking some features like advanced fan controls. Overall, it's probably fine unless you're nitpicky like many of us are. I think the difference in price is justified going with the Z170-A or Gaming 5, but only because I know specifically what I have to have and what I don't. For you, it's probably ok.
It has everything else you'd expect, like an additional CPU_OPT fan header for water cooling and 3 system fan headers. I kind of like to see four system fan headers in addition to the CPU and CPU_OPT headers, but even the gaming 5 only has that many so it's really kind of a Gigabyte thing on the Z170 mid class boards. I'm sure you'll be fine with any of those boards.
I did see mention of a bios bug related to memory on the XP-SLI though, so you might want to make sure that has already been addressed in a bios update before purchasing that model.