I personally would go for the Acer all day. Offers pretty much the same as the Benq but at WQHD which just looks better. Almost twice the amount of pixels and a sli 970 setup is fine running this. At least in games where it really counts to have that 144hz. I mean you wont be getting 144fps+ @ 1440p in games like GTA V or Shadow of Mordor and stuff but you dont need them there. If you still want them you can just lower to 1080p. Also G-sync should really help the 1440p.
Greetings