I bought their Zig M1911 .45acp probably 6 years ago. Absolutely LOVE it. I have not checked to see if GI or US commercial parts fit or work on it. Gonna have to check that out one of these days. It does like the Chick McCormick Custom stainless mags I bought for it. Had trouble with a couple of the cheap GI-style mags before them.
Mine came with a single Mecgar magazine, and it is fine. Works well every time. Which is, of course, what you want from a magazine. OTH, if you want more than 8 rounds, you need more magazines.
The first two I bought were either old GI, or copies of old GI, from the local surplus store, and one worked most of the time, and the other not at all. When I started getting the Chip McCormack mags, each of them has functioned flawlessly and I can get them out at the base. I've not seen a Mecgar mag in a brick and mortar store, and didn't care to buy them by mail order. 
