Hrm, I do not see how AB comparisons, even if blind, eliminate the possibility that one player is revealing the compression on the disc and another is not. You are essentially dealing with a non-linearity between the player effect and compression effect. You actually need to compare players and source material (compressed and non-compressed) simultaneously and estimate the interaction effect, which then indicates non-linearity of effects (i.e. each player is resolving the compression artifacts differently).
That being said, I have been underwhellmed by the quality, or lack thereof, of the output stage on esoteric players. It looks like they are using a new output stage on the SA-50 compared to the DV-50 (and SA-60 for that matter). Does that look like the case to others, or am I letting my wishes get the better of me?