I've watched this thread for a while, and now I just have to put in my $.02! I've got an SMC-380 (PPK-sized based in large part on the recommendations of TFLers), and I think it's every bit as high in quality as the Interarms USA Walthers. Because I'd read about breaking-in jams, I polished the feed ramp with some Flitz, a patch, and my pinkie before I took it out (about 15 min. work while watching TV), and it works perfectly. I bought it just to play around with, but it's so reliable and accurate that I carry the thing sometimes.
The KBI pistols are one of those "I can't believe what a great deal this is" pieces, like an E. German Makarov in the early '90s or a NIB Mosin Nagant 91/59 for $70 right now. They're the kind of thing you'd tell a friend or family member to pick up for the value alone.
Joe, I think you might be the first person I've ever heard to have problems with the KBIs. I suspect it's a problem with your mag catch, not the mags themselves (what are the odds you get two bum mags?). Call the KBI parts dept. at (717) 540-4645 and see what they're willing to do for you - there *is* a warranty (Aha! The lawyer in me comes out). In my experience (buying extra mags and non-thumb-rest grips), they're very helpful folks.
cheers,
erich