Yeah, I sort of hinted that might (or might not be) the case. It's not like I was recording a series of identical tracks with each of the different setups and then making my judgment based on playback of randomly selected tracks.
Even that would not be a true double-blind test, and even if it were, I am not sure what the utility of such a test would be. Psychoacoustic phenomena aside, it might be that Setup E would sound good through a Fender but not a Marshall, or another might sound a lot better but only if you back off the pre-amp gain a bit.
So there is a very subjective element, no matter what you do.