I was in the same dilemma a month ago with a RTX 3080 and those two monitors. I went with the LG and so far have been very impressed by it. I originally had a Alienware (Dell) AW3418DW and have owned several other ultrawide monitors. Was a big fan of them so transitioning to a 16:9 felt odd but eventually I've accustom to it. The display can do 3840x2160 @ 160Hz with a firmware update. And most games I've played can easily hit 120fps or more so that extra frequency helps. Nice thing about the LG monitor is that it's an IPS so good viewing angles and overall good colors. With some adjustments my blacks look like they should be black and same goes with whites and greys.