BAD user! BAD! No biscuit!
OK, so I naively edit the document templates in the Forms folder, thinking that the content type would pick up the template changes. Then I notice that the Edit Template link in the browser UI operates directly on the template in the _cts folder, so rather than go manually edit the docs in that folder, I figure I'll just copy the ones I've already edited. Check out the template in _cts, copy the file from Forms over it, check it back in.
So I try to create a new document of one of the content types whose template I have just edited. The new document seems to use the old template, as if none of the template docs have ever been edited. I go back and edit the template using the browser UI link, and that way the edit takes. Apparently there's some sort of magic that that link does that doesn't kick in if you bypass the browser UI to edit the file.
Really really tempted to go back to folding this whole business in a feature package so that it can be completely deployed and completely retracted with a single click.
