In my experience, many many 'goldbugs' are old fossils, completely orthodox thinkers who are threatened by anything new, or both. A fair number of them are actually just kind of stupid...and a much greater percentage of the silver-bugs fit this description. There are a few exceptions, and I'm certainly not surprised to see Rickards evaluating Bitcoin critically. Keiser also. BTW, I'll bet that Rickards read and understood more about the technical nuts and bolts of Bitcoin in 1/2 an hour than most Bitcoiners will ever know (cypherdoc.)
I could have seen Denninger going either way. He disappointed me by being close-minded in spite of the fact that he has the technical skills to understand the system readily.
I dunno if Sinclair will ever weigh in, but I'd love to see his read. I'm afraid I would be disappointed though.
G. Edward Griffin likes gold backed government money but says he's open to the free market and private currencies competing:
http://www.youtube.com/watch?v=T_hBhymFfm8#t=15m22s