rca plugs - comparisons?

MrT,
your idea per se may be sound. We've trodded similar paths around here. Only you forgot to mention that the technician must be a master solderer. If he is not, and there is a difference in soldering from plug to plug, you'll be listening to solder joints and not to what you are thinking you're evaluating. We found that out the hard way.
Also we did not take cheap wire as you suggested, because we found those unsufficiently revealing. We ended up with better XLOs, Nordost and NBS wires and then did hear differences in our panel. We ended up with NeXtGen and- surprisingly- with a cheapo but very well made Chinese copy of the Nakamichi plugs.

Quite right Rodmann, that's what we did and see that you have good and firm metal to metal contact before using your solder.

Mrtennis, Pjwd,
you are indeed quite right, I think. Crimping or a good screw-down connection is - theoretically at least - to be preferred. If however soldering is done right and you manage to get a good and tight metal to metal connection first before applying a touch of solder - we at least - could not really hear any difference.
By the way, while doing these experiments, we found out to our dismay, that the original soldering on those quite expensive cables we used was terrible, to say the least. More often than not, metal to metal conduct was not made, but the joints just bathed in solder. This experience motivated the members of our group to check and resolder all our wires if necessary. The results, I assure you, were
staggering. ( transparency, micro-dynamics, resolution in general)
Cheers and happy listening,
Detlof

Very good point, Sonic_Genius! Our gear in those tests mentioned didn't however. Our jacks were premium ones. Should have mentioned that.