I'm also seeing a lot of MagTech brass in .45 Colt lately. It will be headstamped "CBC", and have a heavy cannelure. It's also good brass. It's manufactured in Brazil by Companhia Brasileira de Cartuchos.
I don't load a lot of .45 Colt, maybe 2,000 per year, but all the brands seem to hold up just fine. The biggest problem is a lot of dies over size the brass, as evidenced by the severe step produced at the base of the case after sizing. I have one carbide sizing die that doesn't do this, so my brass lasts quite awhile. The older steel sizing dies are also generally easier on .45 Colt brass, but they necessitate the use of case lube, just like rifle cartridges.
Hope this helps.
Fred