It seems I have a same issue see my thread -
http://rog.asus.com/forum/showthread.php?52231-Blurry-text-and-g-sync-flickeringWhat is your PC specs?
I could not return it in my country, so I contacted ASUS service and they answered that they will look into this problem. You can write them at the support section of asus.com.
Still having to endure all that bluring and flickering,
Intel i5-2500K // ASUS Sabertooth P67 MB (BIOS 3602) // 8GB RAM // ASUS Nvidia Geforce TITAN (BIOS 80.10.39.00.0A) // Windows 7x64 with all latest updates and drivers // ASUS ROG SWIFT PG278Q // ASUS RT-AC68U