Success! I think the threaded insert is the perfect answer to building break-down cabs... at least of the cocktail variety.
I just got a cocktail kit and ordered a bunch of threaded inserts from Woodcraft.com in anticipation of seeing what I could do with them.
I put the cab together using about half of the wooden dowels. I laid out my L-brackets, marked the hole-centers, took the cab back apart, used the proper sized drill bit, drilled the holes, used my drill with a flathead screwdriver bit and drilled in the inserts.
No drill press, no jig, no fancy tools needed. Just a drill and some bits. I can't say they were all perfectly 100% straight, but there's only one that
doesn't look perfectly straight. It was the last one I did (at ~3am) and it went into the hole at a angle. My fault for being sloppy and careless.

I put the rest of the dowels in, put the cab back together and started threading in all my bolts. Brilliant! Feeling the metal bolt against the metal threads of the inserts is awesome and I have no concerns (yet, at least) that this is going to break apart on me. It seems solid as a rock. And now, I can take the whole thing down whenever I want. I love it. Definitely worth the ~$20 I spent for the hardware to do it.
Some pics:


