Manitunc, This isn't "60 Minutes". We're just a bunch of guys shooting the crap. No one but us really gives a hoot what we write here. I have heard the stories of reviewers hanging on to equipment sent for review purposes for my entire 35-year audio life, mostly from guys who had first-hand information, meaning they were not just repeating gossip. Therefore, I credit the stories. However, I would never name names in this forum; I think that's reasonable prudence.
On the other hand, I agree with you in that because I have no such evidence to support the notion of outright collusion between reviewers and manufacturers, I would not make such charges. I do charge many reviewers with bad writing, however, and with simply cutting and pasting into their reviews hyperbole to be found on manufacturer's websites and in their product brochures. This is partly because the great majority of them know very little about electronics.