The biggest gain is in "end user friendly". Something that seems to be forgotten all too often.
And fexibility.
And usability.
And content creator friendly too.
And making the most of the 8k surface. Reducing "lost" and unused space without loosing quality.

**On a QUALITY note ;
**Any end user can Always reduce texture size if required. (Thinking background figures here, to reduce memory load)

Increasing texture size is IMPOSSIBLE without loosing quality.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!