I own curved 21:9 monitor, 34''. What I can say is that it absolutely doesn't matter, basically what Krogoth said. The curvature is way to low to change viewing angles or distance to eye in a significant way.
That doesn't mean it's a bad thing - you adapt very quickly and stop noticing it.
As for desktop use, it is really great to me, but it requires some tool to divide the screen into sections, so snapping windows to those sections is easy. I use free software called GridMove, but there are actually many options for that, including some nice-looking commercial tools, like this one:https://www.nurgo-software.com/products/aquasnap
With a tool like that you can work in similar way to having 2 monitors, only you don't have bezels in the middle and you can change how the screen is divided. For example, in my configuration I have a big window in the middle of the screen, taking about 50% horizontally (I use it for browser and other main applications) and 2 smaller parts on left and right (each has a slightly different size though, to fit software I'm typically using there). And any time I need to, I can easily use the whole screen for one application, for example for big excel table.
My experience with desktop usage is actually better than with gaming, as some games are not working perfectly with 21:9 ratio, UI is not designed for it in general. Also for more demanding games you can't simply divide the screen resolution by two to get better FPS, as that would be too few pixels vertically.
One more thing that is irritating is YouTube, which still doesn't support 21:9 ratio and you end up with black stripes on the sides, top and bottom. There are some browser plugins to fix that, but they don't work very well.