I hadn't looked to see if KMC still made the 8 speed chain in gold. I do know they still make the 9 speed one though. It "should" work just fine on the 8 speed system. I used to run KMC 9 speed chains on my 7 speed cassette and never had an issue, but that was with 7 speed Shimano mountain groupset (Deore LX M550 on my M700). I run 10 speed chains on those bike with 9 speeds(including the MicroShift Advent 9) and don't have problems with that either, but everyone has different opinions and experiences with that.
Regardless, I am pretty sure that the groupset shifts pretty nicely, I still think that my aforementioned 7 sp. M550 derailleur from my M700 is the smoothest and fastest shifting out of all of my bikes. It makes ZERO noise going up or down the cassette, unlike the SRAM 12 speed derailleurs I have on several bikes which always have a nice "clunk" when shifting from 10th(15T) to 11th(13T) and and 1st (50T) to 2nd(42T) every other gear change is silent up or down . No amount of tuning has gotten rid of it either, I just except it now.