What's not to like about any of them?
I thought about your comment "end of an era" and wonder if it, in fact ushered in a new era by way of only producing one metal at a time. This was something quite different for them at the time.
I remember when the yellow gold version was introduced that it seemed very odd that the other metals were not made available at the same time as all others (production pieces, not including limited edition pieces) had in the past. And if I'm not mistaken, was the first reference to experience this.
I am a visual kind of guy and prefer certain dial colors and I gravitate to the rose gold version and if buying one today, the R would be it.