i had spots on my first prime (BCOK) but exchanged due to GPS (also had haptic feedback issue too).
Second prime (c10) has a couple spots in landscape about an inch from the bottom of the screen near the center. I have "kept an eye on it" as far as noticing it only when I'm really on a white background or anything. I usually use it for reading and/or taking notes on PDFs so I surprisingly haven't been bothered by it AT ALL. I actually forgot they were there until last week.
Anyways, if it gets any bigger or I get more spots, I'll send it in over the summer...
Nexus 7 FHD: 4.4.2 stock, unlocked bootloader
HTC One XL: CleanROM 7R2
Nokia Lumia 800: WinPhone 7.8
Retired devices: Asus Transformer Prime, Nokia E62, Nokia E61, HTC Fuze, HTC Tilt2, Nokia E72, HTC Inspire
Hit thanks if I helped you please