Well, if possible try to demo in store before..you might not like it..
Yes I bought the LG 21:9 monitor because I did use two monitors before..but then one them died..
I will give you my conclusion, atleast with the LG split screen software there is still an advantage with using two monitors. When I had two monitors, I did tend to all of the time to watch movies or video clips and streaming on the right screen in full screen mode, this was not possible with the LG screen even with the split screen software, cause you can't put a program in fullscreen it will cover the whole screen..
I was dissapointed, I thought on youtube I got the impression that with the split screen software two seprate screens would show up in windows... that would be the ultimate..
Yeah so I guess it does depend how you use it... sure it was nice when I was using it in DAW but for the other stuff I did really prefer 16:9.
But for me personally, the 21:9 was too wide for my desk it did actually cover my racks I have on the desk on the sites...anyway I sold mine after two weeks.. it did also made me clear to me next time I buy a monitor it must be higher resolution then what I have now.