Well all WQHD 1440p G-Sync monitors I tested had clouding issues (like vertical clouding strips) which is probably AU-Optronics fail becaus all newer Full HD 1080p don't had these issues.... I think its also very hard to get one with a good uniformity currently, unfortunately
With IPS panels I have the same problem, I cannot deal with IPS glow. The viewsonic I had (G-Sync), had the best glow abilities, but even here I couldn't live with this glow. So thats why I also stick to Full HD atm. What about the new Samsung / AUO / Philips monitors with VA 144 Hz ? (but "only" freesync :X) -> Samsung C32HG70 / Samsung C27HG70 / AOC Agon AG322QCX / Philips 328m6fjmb.
Maybe it's currently just worth to wait for other monitors before you spend hundreds of dollars into a monitor with disatvantages you cand deal with.
To calibrate I even don't use test screens. I calibrate color temperature just on the desktop (or sometimes I change it in a game) as same as brightness. Gamma is a bit more difficult while in some content my settings looks good and at other games it's sometimes to dark. On desktop for TN even Gamma 2.4 is not bad, because of TN viewing angles.
The one and only thing you can do without hardware calibration is to lower the gamma in your graphics card setting with some test screens like or tools like this (sorry coudln't find in English): https://www.eizo.de/monitortest/
-> Choose only gamma and click on "test starten"
Explanation: Change the grayscale of the logo using the slider until the logo fuses with the background as much as possible. The displayed value corresponds to the gamma value of your monitor. So you set that Gamma value in the tool which you aim for and change gamma settings in the monitor OSD. If they don't "hit" your desired gamma value then you have to change within your graphics card settings. I hope this will help
This is something I already post in another topic. I hope it can help. But like mentioned, you dont need hardware calibration if you don't use photoshop. If you want use photoshop, especially for print, hardware calibration is pretty important.
... in the end... sorry I cant help you, but current WQHD monitors has some issue which some people can deal with and other can't. If the Asus pg278qr clouding already disturbs you, you shouldn't try the dell, while dell has very noticeable color banding issues and the acer and also the dell had the same clouding amount as my asus pg278qr. Maybe It's worth to take a closer look into the new 144 hz wqhd va panels. I currently stick to 1080p, and I also will give the new VA's a chance soon, when I finished my "Freesync 144 full hd tournamend".