I quite like how they say you get 63 rows in excel in uhd instead of 46 rows in full hd..then u notice the subtle full hd in 21:9 format..
because as far as excel goes I get 43 rows in 1280x1024 at my 19''..so yeah..nowhere near as good for productivity.
it may have the wow factor for 21:9 and be nice for movies but then again anyone who can afford a 4k monitor prob has a big screen tv anyway.
its also not really 4k but a half-way.
id rather wait for true 4k at 34'' or higher from a reputable manufacturer, at proper format for productivity and gaming.
also, there are a lot of people complaining about scaling in windows at 4k monitors when they have not tried any themselves. All the reviews of actual users I've seen with windows 8.1 do not mention any serious scaling problems, just trivial stuff with some old software. So please, stop the scaremongering..