I've used both, and I prefer using multiple monitors over the ultrawides. I've found that multiple monitors gives me much more flexibility, as I can orient them in a manner that's most conducive to the task at hand (for instance, being able to aim one monitor towards visitors to show them things).
But, honestly, my preference is a slight one -- if I have to use an ultrawide instead, that's actually fine.
I use both at once.
Left monitor is a Dell U3818DW 38" curved (3840x1600)
My right monitor Dell Ultrasharp U2718Q 27-Inch 4K IPS Monitor (3840 x 2160)
If you price them out, they are are very cheap per day - $4 a day.
I've done both and only use "large" monitors now. Be it ultrawide or large high resolution monitors... I can't stand the bezels and turning my neck larger distances/more often always bothered me. I think this is just one of those personal preferences things though.