Re: Why so much more love for the old Rg550's vs the old 560's?
It's gone in cycles to be honest. 15 or so years ago the 570s were the rage, you had to have that rear routed body to be a cool kid. Then the 550s became the ones to go for, presumably because it's closer to the original JEM777 in design.
The 560 with its HSS design has always been the odd cousin, with many prolific posters preferring the HSH design of the other two. If I had to put money on it, I'd say that it's the neck single coil that is seen as,the weak spot on the 560 compared to the other 500 series guitars, but it's exactly that same neck single coil that sets it apart as the one to have for others.