I still need to "digest" the whole concept, as there are many side issues that could (and should) be discussed here. Of course, from a philosophical standpoint (as always!)
I think that even if there are a couple "flaws" with the movement, you'd still end up with a better Catholic than most Catholics are. Because even if there are two downsides, you'd be betting the 4 or 5 "upsides" which make it a net positive, or at least better than average.
Like I said, let's discuss the movement, what we can learn from it, and how each one of us might already qualify as a "Plain Catholic" -- and how we'd not qualify.
So the first question is, what is required to be a Plain Catholic? We need a distilled list, something like one of their websites stripped of all the Scripture quotes.
What is the sine qua non (without which, "no") of being a Plain Catholic?
Matthew