I assume you mean this one:
You won't mistake it for a higher end product like Tactical Tailor or SOE but it works well. The pouches each hold 2 30 round mags. Thermold mags are a little thicker and it will hold two of those but will be very tight. No problems with aluminum mags. It also has two pistol mag pouches.
I personally find it a little more difficult to get the straps to stay just where I want them for comfort, but that kind of thing varies widely between different people. It is still comfortable to wear and that fact that it only holds up to 8 AR mags and 2 pistol mags means that you won't be hanging enough weight on it for comfort to really be an issue.
As with pretty much all other gear of this type, all of the buckles and 'hardware' are plastic. I haven't used mine very much but it seems durable enough. You certainly can't beat the price.
Yes, Blackhawk makes just about all of their gear overseas. Or more specifically, Blackhawk has contracted with a foriegn company to make their gear for them. That company was originally doing all the work in Korea but has moved work to factories in VietNam.