I think 32" is too big on a monitor, 27" is the magic number… but I guess this fills someone’s need. 40" is insane on a monitor.
Now the terrible:
#1. No HDR on this expensive monitor.
#2. No adaptive sync (super standard to offer FreeSync on a monitor these days)
#3. White is a warm color on this monitor. This may annoy a lot of people.
#4. There is zero height adjustment on this monitor, enjoy your neck pain.
#5. Calibrations are pretty gimmicky on this monitor as there isn’t much to be gained by adjusting the stock settings. (sRGB is a joke on this)
Pros:
#1. 4000:1 static ratio would be awesome if this had HDR, still impressive range.
#2. DCI-P3 gamut - google it if you don’t know what it is.
#3. See the high dynamic range as it’s pretty hard to beat.
Super Pro:
You can use Picture-In-Picture with this monitor and have it display multiple inputs on this very large real-estate.
I jumped on the 40" 4K monitor bandwagon when Philips came out with their flat unit a few years back. I don’t game, but rather do work on my computer. Going from 2-3 1920x1200 and 1900x1080 monitors, having ONE 3840x2160 monitor is great! Spreadsheets are easy to work on, you can have lots of windows open if needed, if you do engineering then all kinds of CAD are just awesome since you have so much space to play with to do work. Text is at a readable size at 100% unlike a 27 or 32.
I first put my monitor on a ream of paper for the “right” height. Also you can mount on an arm if you need to fiddle adjustment wise. I haven’t moved mine in 3 years.
Its fairly inexpensive… I paid $800, and was very happy at the time. so 1/2 the price for curved is pretty good in my book.
My 2 cents on why you should go with 40" 4K.
Found cheaper on amazon
https://www.amazon.com/AOC-C4008VH8-Class-Curved-Monitor/dp/B07BSSMNPF/ref=sr_1_1?ie=UTF8&qid=1547730663&sr=8-1&keywords=c4008vu8
[MOD: not the same model]
Didn’t compare the specs yet, but that link is for the AOC C4008VH8.
The one for this Woot listing has a different model number (AOC C4008VU8-B). 
That is a different model number with different specs. For starters, it has 16.7M Colors.
That one in that link is not 4K!
I would never use anything more than 27" for home/gaming however for work I previously was using a quad setup of 19" monitors and will gladly say that a 40" has its place. At 4k you are basically just utilizing four monitors without any bezel spacing dividing them.
Anyone who’s looking at graphs/data/emails/files all day long a 40" 4K is a great solution.
I bought this monitor the last time it showed up. I like the size and 4k resolution. I will say it has a crappy refresh rate. So if you try to play games or watch videos it has a bit of ghosting/blur to it. If you are doing normal “work” on it. I think it works great for that. I will add that at 40in it is really tall. But getting essentially 4 “normal” screens on the screen at one time is really nice. For the money I’m not disappointing but I may buy a different monitor down the road as I do play games from time to time on my pc/laptop.