I have several of these cases that I picked up from the manufacturer at their booth at the SHOT Show. The base is stainless steel, and it takes their proprietary dies to load them, or you'll pull the case apart during sizing. They're pushing them towards the military as a way to make the cases lighter, and they're also pushing them towards the domestic markets as being reloadable dozens of times. I forget the number of reloads they claim to have gotten, but the number 40 sticks in my mind.
I get so many 9x19 brass now when I buy the brass from our range that most of it goes to recycling, so I doubt I'll be investing in the dies to load those two piece cases during this lifetime......
Hope this helps.
Fred