Well I’m 8 months into GX with X9 Cranks from 3 years ago.
I’ve replaced one chain in that time which was over the 0.75 mark as I got a bit distracted but the cassette is holding up fine, it seem like a tough one.
According to my strava logs it’s done 1880km (chain replaced at 1800) in a good variety of conditions but mostly summer. Very little love and attention just a hose and lube unless I’ve gone international.
Based on that I’d expect to put another couple of chains over it and get up closer to the 3-4000 mark hopefully.
Range is good, price is good, weight is good. Winner for me.