I bought some and I havent ran them all (ammo cost and all), but they look exactly like the chinese.
I think I did run 1 just to see how it would do. I cant recall having any trouble from ANY drum for an AK.
Hopefully others can be more helpful, but I would have no objection to ordering any of the drums available (Romanian, Chinese, Bulgarian, or Korean).
If I didnt have Romy drums, I'd order some for that price...as is though I need Korean and bulgarian so I'd be stuck ordering from centerfire for $70 on their Korean ones.