I have a montecarlo ATI stock for my sks and i had to glass bed the recoil lug to make it fit right and had to mod the stock to fit the gas tube too. ATI stock fit wasn't that nice and fitting was required but i fail to see how that is Marstar's fault. ATI stocks live and learn.
Can't comment on your customer service experience but when i called marstar on a scope issue they said ship it back and we will look into it. Pretty standard stuff for mail order.
That being said, i will stick with original stocks for SKS and mod those to do what i want cause they are easier to work and inlet than plastic ones. And i prefer the feel of the lumber, I think it has more personality.