A:Answer Short answer: both are great monitors for gaming, depending on what you're looking for.
Long answer: I was between this monitor and the RL2755HM, which is a larger version of the monitor you specified. Both have extremely low input lag, but the difference is in the display panel. Asus is IPS and BenQ is TN, which basically means the Asus monitor will have more saturated colors and the BenQ will look more washed out by comparison. The BenQ monitor you mentioned is specifically designed for console gaming and used in the Major League Gaming circuits, and it ends up having a very fast refresh rate of 1ms. The Asus monitor is 5ms, but I have to tell you, I personally can't tell a difference. Color was important to me, because I'm using this monitor for more than competitive gaming. Aesthetically, the Asus monitor looked better to my eye, more mature and high-end in its design, whereas the BenQ is built for gamers and has a gamer-focused design. I bounced between the two monitors for a long time and ultimately ended up on the Asus, but you can't go wrong with either monitor.