Higher price and I think it only has a 1 year warranty
Why can't someone just make a perfect 27" 1440p monitor? What would you buy right now Badass?
Has a 2 year warranty and can be easily upgraded to 5. Dell don't even let you extend after purchase. You can upgrade whenever you want. Not to mention QC is near perfect (I have 2 incomprehensibly small yellow blotches of backlight bleed that can be only seen under complete darkness from a specific angle - the rest is the regular IPS glow which I'm perfectly happy with). Customer support replied a few hours after my request, not days and their website is very, very easy to navigate.
The stand also has a nicer design, although it doesn't swivel, but if I really wanted it, I'd buy myself a vesa stand. The matte coating is literally perfect, there is nothing like the cross hatching and there is no sign that the matte coating is even there.
OSD is really nice, if not a tiny bit fiddly due to the touch buttons and has a fair few options - low response time mode is perfect and leaves no compromise on image quality whatsoever. Looks exactly the same as otherwise - and I can actually play games like CS:GO with no issue, unlike on the higher response mode I must've left the Dell on because the game was nearly unplayable.
Negatives? Standard colours out of the box were too yellow on the whites for me (10-bit), so all I did was change the colour temperature to a cooler level and turn down the contrast a tiny bit which gave me white looking whites and otherwise similar colour quality to the Dell, albeit FAR more punchy - almost like AMOLED, which I personally adore.
There are some issues with image display in some applications, namely windows photo viewer, where colours appear a little drained - this is to do with the management of the screen in Windows - It looks like the sRGB mode on the monitor which is sort of depressing to look at because it crushes the natural wide gamut of the screen xD I'm sure there is a config option but it doesn't bother me at all. All I've done by buying a 10-bit screen is future proof myself since we should start seeing 10-bit come in more over the next 5 years.
Other problem I had was with HDMI - the monitor is very fussy with EDID I think, couldn't get it to work with a PS3 or Xbox at first, but later got the PS3 working flawlessly - but the Xbox refuses to work. This is not the first time I've heard of something like it, and the Xbox also refuses to work on one of my other screens now so I think it's just a terrible implementation of HDMI. Got it working fine with my MHL connected smartphone too - it works flawlessly with any PC.
So while this monitor is not perfect, I personally think it's one of the best - if not the best - 2K monitors out there. My advice is to pay the extra money. I just cbf with Dell and don't regret spending more to get a higher quality monitor and level of service.
EDIT:
What I will say, is that many new 2560x1440 monitors are coming out and I think they are based off of this LG display, as this monitor is just about the newest one to market. There may be some cheaper ones soon and they seem to have an extra port or two than the LG (LG has DP, HDMI and DVI but no VGA - not that it concerns me XD)