Sad to hear your troubles, But I was not responding to your post.
It was example how scaling looks. BTW, do you see improvement in WoW with Metal over OpenGL? In performance, for example.
The performance of WOW seems to be comparable at first glance. However the image clarity is much sharper now at 5K with a frame buffer of 50% in Metal compared to it was in OpenGL before Metal was available.
The frame rate is all over the place. The old zones and in doors will get into the 70 to 100 FPS range. New zones are around 45 to 50 FPS.
Due to the in house connector used to get around the lack of any motherboards that would connect a 5k screen when it was developed an external GPU on an iMac will only run another external screen making it a bit pointless when you have that lovely 5k beast in front of you.....
Maybe if I'm lucky Apple will release a 5K monitor even if it takes two thunderbolt 2 ports to drive and I can upgrade to a Mac Pro. Although even that probably can't drive a 5K screen in games without making Crossfire or dare I wish SLI work in OS X in a new hardware update.