Better build quality? Better sound?
Nah.
Sony's do have the upper hand with the impact but the se846 does provide better audio overall and they are sturdy as screw*. I've mistreated mine quite a lot and they don't have a scratch.
I use my Sony and jvc zs2000 while gaming for the extra bass but never for audio, they are not well suited unless you only hear hip hop and similar styles even after eq / amp / dac/ you name it.
But if you have 500 I would suggest save 250 more and go for the audio64 u8, better audio and punchy bass.
Edit.
I own the EX800ST, xba-a3, se846, jvc ha sz2000, and u8.