I really dislike the screen of the OP3T and I'm probably going to return mine because of it.
Unfortauntely I can't post an image comparison I made but you can probably see it for yourself: get some app with sharp edges in the UI and black on white text (Now for reddit, for example), you'll notice a bit of color fringing around the text, typically some green above and purple below the characters' lines. This makes text look somewhat out of focus and uncomfortable to read.
It really sucks compared to my Nexus 5's IPS screen, sure more vibrant colors but what use is that if it can't display text in a readable form?
Too bad, I really like the rest of the phone. Now I'll have to go back and look for another affordable dual sim high-spec phone.
(This is my second OP3T after I returned the first one believing this was a manufacturing defect, after some looking around it seems to be a result of the screen being a PenTile AMOLED display at a too low resolution for the size)