How well does this monitor OC?

I am getting an ASUS PB277Q which is 2k/75Hz. How well does it overclock? Also, would it be better to overclock using HDMI or DP?

I am wondering because for $60 more, I can get the Acer XG270HU which is 2K/144Hz.

I'd rather not spend the extra money, especially if the PB277Q can reach 100Hz.

My system is an i5-6600K/GTX 1080