I personally own and use the kz zst and the kz zs5's dailly, and can totally recommend both of them.
amazing sound for the price, plus the replaceable cables are a huge plus for me too.
Gpu usage is inconsistent as hell in games drops from 99 to 80 and even dips into the 70%
When this happens the fps drops with it.
Power usage spikes too.
Yes I will test as soon as I can.
Could it be overheating vrm's?
I also notice when the gpu usage and fps drops the power usage of the card drops too.
Yes I run an undervolt.
1000mv at p6 1050mv at p7 and memory
+50% power limit and i use 70% fan speed