Are you talking about an ATI Omni lower? Keep us informed. Anything combining zinc and firearms kinda scares me, but so does an all polymer lower. Though I do have a Polymer80 %80 percent lower laying around, but that will probably end up as a dedicated .22lr build.
I agree, the polymer lowers scare me too. My buddy has an Omni, it failed and he had to send it back under warranty. The spring and detent on the forward takedown pin blew out the side. Its great that they replaced it, but the hassle of getting it replaced and the fact that companies don't hang around forever worry me. For the $20-50 difference, I'll stick with metal lowers.