Because for one, it is a Freesync Monitor. Most people at that time during its release has an Nvidia graphics card so Freesync is of no use. So might as well go for the G-Sync Acer XB271HU monitor
Secondly, this is a TN panel whereby the XB271HU is an IPS panel.
Thirdly, 144Hz (XG270HU) vs 165Hz (XB271HU).
But actually, only the 1st matters most since if you have Nvidia GPU, go for XB271HU and if you have an AMD GPU, then go for XG270HU. The end.
I have a Nvidia card. But it scares me to pay 2x the price.
XB271HU would def be my top choice but.... a guy's gotta feed his family first
Free sync is so common it's as if buyers are barely paying any mark-up, while Nvidia is just ripping off gamers
My 1070 should output about 75~100 FPS on most games at 2K
Hence why I'm mostly concerned about the color of a TN panel, which usually differenciate one from an IPS panel, your second point
It is 8 bit though, so I am assuming it has decent default color reproduction but want to hear personal experiences from y'all
EDIT: Just saw it went from 11 stock to zero on Lazada. So hopefully someone has bought one as well XD