I ran on 16:9 for a long time as my main rig was being overhauled. Now I'm on three screen surround at 5760x1200, and it is a world of difference. I did have some concern about the FOV though, which I've now set to the minimum, due to the "fish-eye" distortion at the far sides. It gets very annoying as things magnify to ridiculous levels and ovalise.
As a result, I'm considering a single 21:9 screen after following ObsidianAnt's videos for a long time. I think the reduction in width reducing the distortion, coupled to a single screen uninterrupted by bezels from three separate screens might work for me a lot better, yet still provide enough extended field of view to be a great compromise.
These new slightly curved IPS screens with 1440 vertical resolution are becoming more affordable, and also the pixel response times are coming within range of the low and mid range TN panels. Some of them, like the newest bleeding edge Acer Predator X34s, which have higher refresh rates like 75Hz plus, also have FreeSync and G-sync now.
Looking around, there are a number of good 60Hz ones at the mid-range price bracket that would be more than good enough too, if you aren't fussed about the aforementioned features.
I'm still mulling it over. As much as I'd love a Predator X34, it's very new, and pretty much alone in the market making it very pricey, and no doubt next year, rivals will pop up and a revised version from Acer... So I'm uncertain whether now is the right time for me to move from triple screen. However, for someone gaming on a 16:10 or 16:9, and wanting something more, I'd say go for 21:9 now in a price bracket you can afford.