building cabs for a living. Regarding pot metal, I am pretty sure if you buy the cheapest woodraft brand you can get that, you do get what you pay for. I don't use them often enough to know what brands are best but the Blum recommendation seems like a safe one.
Concerning the Blum hinges, the particular inexpensive ones that I buy
50 at a time, I am amazed that they are can be bought for about $1 each. There are several parts in each one, 9 IIRC, and this is all stamped steel. And NO slop. Then they are stupid simple to install and adjust. I have been using this type hing for 20+ years and have only had 2 hinges to fail. The ones that failed were Blum and discontinued. Blum replaced the hinge with it's replacement +2 more to match the rest on that particular door. If you haven't used them they well worth a close look