Could you ask OCUK as to why it is listed as B grade? Just give them a ring.
B Grade items may have been used, have damaged packaging, missing accessories or a combination of these (Motherboards may be missing I/O shields).
Some items may have scuff marks or slight scratches but should otherwise be an operable product.
If it's a customer return - and that is all the info you are given - then it's highly likely to be because a customer found an issue of some sort with it.
Could be refurbished by manufacturer, in which case it would be like new usually and the issue fixed.
Could be ex display or used internally at OCUK office.
Could be damaged in transit or warehouse to the external box only.
90 day warranty on a monitor is risky, but I guess you will spot issues normally instantly.
I've bought a few b grade monitors from ocuk and all have been spot on tbf.
They don't usually tell you the condition of the item if you ring them as they won't have that information on hand and they might have more than one so you might not get the same one they are describing to you.
Definitely worth a try, just bought Corsair Xeneon 32" 4K, and it's perfect, no BLB, no DP. Only way you'd know someone had had it before was the "label" you get on new monitors detailing it's features wasn't attached to the screen, but was still in the box, all packaging was spot on, and box had obviously been resealed, everything bagged up as new, no marks anywhere no scratches etc
I've got to say the extra fidelity at 4K is incredible, I ummed and ahhed for a good month before taking the plunge, considered whether the £500 would be better spent on a GPU, not even close, frames are one thing, the experience is quite another, no amount frames can replicate the immersion or absolute splendour of 4K. The textures up close and at a distance are mindblowing, I had a very nice 1440p monitor (AD27QD) for 4 years and I was very happy with it, but this Xeneon is something else, the brightness and color gamut are amazing, everything pops. Build quality is superb, the stand an acquired taste, but I love it, got quite a bit a Corsair kit, RAM, AIO, so syncs in well with that eco system. I was going to buy LG's 32GR9U-B for about the same new, but it didn't have Quantum Dot as this has, or Nano like the LG 950B so that swung me towards this B-Grade. By all accounts it's not quite as good as the 950B, but I doubt i'll notice it as much as I would have spending another 30% or so.
Definitely give the B-Grade monitors a shot, nothing to lose except some inconvinience if it's not spot on, this was going back if it wasn't perfect. And the trade off you might have to make between 4K + less frames and lower settings vs 1440p + higher frames and settings is definitely worth it.
To think my orginal plan was to get more real estate but at 1440p, what an idiot, just goes to show, do your homework before you put anything in a basket.