Ultra wide are sold as being amazing for productivity and movie watching. I don't disagree, but there are a few gotchas you should know about.
For productivity ultra wides are extolled as the equivalent of two monitors side by side. For me, the width of the ultra wide is a bit shy of what I'd like for two windows side by side. Don't get me wrong, it's doable, but with my old eyes and jacked up font sized, half a 34" monitor wide is too skinny a window. I usually end up make one window take up 2/3s of the screen and another window take up 1/3. It's too bad the windows snap feature doesn't allow you to do this automatically. If you have a good software solution for this holler.
For movies, especially ones available in 21:9 the 34" ultra wide monitor is INCREDIBLE. The only problem with watching movies on the monitor is it's so big, you need to actually back away from the screen. There is one gotchya on 21:9 content it's hard to find. Most of you tube is 16x9, and netflix only encodes in 16x10.
Luckily for Netflix there is a browser extension you can get called called ultrawide display aspect ratio which removes the letter boxing.