This summer I'm looking to update with a new monitor and am trying to decide between jumping to a 4K monitor or get a super widescreen aspect ratio such as 21:9. I use my rig primarily for productivity and generally keep many apps open at once, however I also do game in my free time. So really, I'm just trying to get a feel for peoples thoughts. Thanks!
If it's between 2560x1080 and 4K, then get 4K. If it's between 3440x1440 and 4K, then it's a tough decision.
It's a tough one. With 4K, if you have scaling at 100% in Windows, you can have 4 windows open at once and it will be like having four 1080p monitors in a square configuration.
With 3440x1440 it would be better to use it to have two windows open at the same time. 21:9 would be more impressive for gaming, and use less gpu power.
21:9 is only viable at 3440x1440 in my opinion but the cost is a major issue. I recently got a 3440x1440 monitor over a 4K and I'm really happy with it.
Something else to consider is; do you want or need multiple monitors, or the ability to have something open on a separate display while gaming?
I've been considering the same choice you're faced with here, and I've decided (eventually) to go with a 4k display instead of 21:9. The reasons for my decision are as follows:
-4K will have higher pixel density/sharper image. -I play some FPS games which, IMO, are better played on a single display instead of surround or ultra-wide because you can more easily focus your attention where it should be and not get distracted by what's off to the sides. -Some games in surround or ultra-wide don't scale well with the extra resolution and the textures are stretched and distorted at the sides. -I can still have room on my desk for a dedicated separate display where I like to keep MSI afterburner and a few other programs open and running while gaming. Unless you have a big desk, this can be difficult to do with an ultra-wide, or you must position the extra display above you main.
Just some food for thought. It really boils down to your own needs/preferences and specific setup as to what is best for you.
The solution I'd like to see is the same vertical resolution as 4k in a 21:9 display. I know that's a ways off, but with 5k support coming to some graphics cards and being included in the latest iterations of the standards, 21:9 with the vertical resolution of 4k would become more feasible. Now if only I could afford to replace my current 1080p monitor :)