I just reread the blogpost (by the parent) that this article cites, and its points all seem correct to me, including that "Mac OS X 10.6.0 was certainly much buggier than Mac OS X 10.5.8":

• 10.6 was not primarily about bug fixes

• 10.7 was buggy and its design was incoherent

• Apple should abandon its yearly release cycle

That said, my recollections from the time are that the 10.6 GM release caused fewer problems than the 10.5 GM.

It wouldn't surprise me if the consensus about Snow Leopard switches to the opinion that Snow Leopard was no better than any other version. That's wrong, but few people still use or remember using Snow Leopard.