I received the new holsters and these ones are a whole lot better in the retention department. A night and day difference. I take back what I said about the company previously, my initial impression of the replacements is that BRC makes great holsters! Also, I've got my PX4 holster needs covered for now. Thanks @medmo for the recommendation.
By the way, while they don't advertise it on their web site, they were able to make the IWB with adjustable retention, so I can dial it in to exactly where I like it. Neat!
I did have to pay customs for a second time since I couldn't prove I had shipped the old holsters abroad, so that kind of sucks - that was another about $50 on top of what I already paid. But I can hardly blame the holster manufacturer for that. (And shipping the holsters back would have been at least as expensive anyway.)