Stop trying to give tech advice.
Acer manufacturer specs
Asus manufacturer specs
The Asus has a superior color gamut and superior pixel pitch (the latter is common with a higher pixel density). The Asus also has better built-in motion blurring and anti-flicker technology.
The Acer can output more brightness, and enjoys a better contrast ratio because of it. The Acer also has a Displayport, not just HDMI, and it supports its Freesync over that port.
Beyond that a question mark is on response time. Monitors basically never hit their MPRT quote. Both boast 1ms, but that Asus line of monitors has a reservoir of reviews showing their monitors delivering response times low enough that at lower framerates, when it's most critical, 100% of pixels are satisfying the image changeover in time to not ghost. Acer has plenty of monitors that can hit 1ms, but this one is so cheap I'm skeptically apprehensive. I couldn't find a real lab that tested it to confirm average partial & full response times. Could be monitor technology has gotten so good they can deliver reasonable response times this cheaply. Best test would be to find a game that puts you in the 40fps-60fps range, and see if you catch any ghosting.
Overall, they're close enough in spec that I think Clifford's recommendation is the most sensible one, and you should give them the eye-test. A lot of guys will bitch about the low PPI of the Acer, but I find that size usually trumps resolution itself, not just pixel density, when it comes to subjective viewing experience. So keep the one you like more, or if you like them equally, return the more expensive one. There's not such a clear winner or any hidden feature/capability you'll regret it later.