I have the ASUS PG348Q, which sounds pretty much like this same monitor (although mine only does 100Hz). I run it from a 1070 (laptop version due to portability requirements).
It is very nice, and a great compromise on using a 4K monitor (I also have). I feel a 4K really needs to be 40" to 43", to get proper use out of it, and avoid display scaling (which for some of the programs I use, just doesn't play nicely regardless of what I do).

So for 6 months I use a 40" 4K, and 6 months the 34" Ultra Wide. I think the UltraWide does win overall, because with the 4K, I find I end up sizing windows so they are not as tall as the monitor, because otherwise I feel like a bit of a nodding dog (or my eyeballs do anyway). The 34" is just about right to be able to keep my eyes focused and notice things on the whole area (plus it just seems easier to move your eyes from side to side, rather than up and down). I would like a slightly tighter curve on my screen due to the distance I sit from it (about 2 to 2.5 feet), but at the same time, it is better than no curve.