The Ruby versions probably have some better parts and implementation than the standard versions, much like my Marantz PM-15S2b has over the PM-15S2 or S1. In my case, Ken Ishiwata took some of what he did with the Pearl series (also limited to 500 units each) and applied them to the PM-15S2b.
Whether it sounds better, I can't say, but they are in demand.
All the best,
Nonoise
Whether it sounds better, I can't say, but they are in demand.
All the best,
Nonoise