I'm guessing many people don't actually realise this, as you it's not always noticeable until you put it next to a quality IPS panel. Next to Dell U2515H, both the XB271HUs looked absolutely terrible. It's laughable that they even call panel IPS with such horrendous whites.
Thats funny considering Ive had a U2414h and a P2414h along with my U2412M and a LG IPS277L