I got the PG278Q (2560x1440) back in Nov 2014 for my brand new gaming rig that I got earlier that same month. It was an upgrade from a Dell 24" 60hz monior. I think I was using a 970 GTX card at the time. Those cards had come out recently too. I was not able to play on max settings @ 144hz. I could tinker with a lower resolution, or lower settings, to bump up the FPS. Also that monitor is a TN panel, and is a lot darker than an IPS monitor.
I kept hearing good things about 21:9 Ultra Wide monitors giving a better imersive experiece. But it wasn't until one day I saw one in person at my local Fry's that I fell in love with it. Holy Smokes! They had a 34" curved monitor on display. It was either the ASUS one, or the ACER Predator. I forget which. Though both use the same panel. I soon bought the PG348Q (3440x1440) and upgarded to a GTX1080. Some games, can play with max settings @ 100FPS. But not all do. And again I have to tinker with the settings. I like to not go below 60fps. I have experiment with lowering the resolution, to try to up the FPS. But I didn't like how it looked.
The PG27UQ looks impressive. But, I'm probably going to get the next version ASUS 34" with HDR (1,000 nits). Whenever that comes out. I think I can use it on my current setup. Or I might need to get the next future version GTX1180 to handle it. Or at least up the FPS with higher settings.