I ended up going with an ASUS PA278QV 27" QHD. I'm very happy with it. The colors look amazing and I like the extra desktop space over FHD. I did have to bump up the font a notch in my editors, but I can still display more on the screen than my old monitor. Using 100% scaling it looks great. Would not want it any larger or smaller. I'll probably get another to replace my second screen. I'm thinking that for 4K, it would need to be greater than 32", probably around 36" - 38" which would probably be too big.
You did a ProArt and one of the least expensive. Nice Choice. You like the text right? One might think it is for pictures, but text, really a Font, has a lot of details that a crisp DPI and good color separation can make out. Some of the precision monitors I have seen were on Font designers workstations. https://www.asus.com/us/Monitors/ProArt-Display-PA278QV/
People don't understand the subject and reply hastily. QHD is not UHD. It's Quad High Definition - 2560x1440 - perfect for 27" size. The "Quad" refers to the fact that it has 4 times as many pixels as old "standard" HD (720p]
I initially bought two HP 27Q monitors and ended up returning both. I love my HP Elitebook and have an HP E243 display at work which looks great. But the 27Q was disappointing. Both my 12 year old Samsung and 10 year old HP 2509m had better color than the 27Q. The 27Q is not an IPS panel. I thought that it was, but confused it with another HP 27Q (older model apparently) that is. I don't know why they still make TN panels. Other than that, the panel was fine, but the ProArt is way better. The text looks great. I spend most of my day looking at a text editor for software development with black background and colored text. For that reason, I really needed good color accuracy. I wish I could have compared more monitors side-by-side and avoided the return, but I don't know of any store that sells a wide selection of good monitors. I would have liked to compare the ProArt, Dell UltraSharp, and LG side-by-side. Also, I wish more monitors had a glossy or no anti-glare option. I can control the lighting in the room where I use the monitor and I suspect the anti-glare film just degrades the image.