When I bring gear home to listen to, I keep it real simple...I just listen. 3 outcomes are possible.
1) it sounds better
2)it sounds about the same
3)it sounds worse
I have taken home 2 aftermarket powercords, 1 sounded about the same, the other sounded worse, both were expensive.
I have tried 3 powerconditioners, 2 made my system sound worse, 1 made it sound better ( I bought it)
In the last year or so I have been trying mainly equipment.
Fom Mcintosh I have heard in my house..the mc252 the 402, and the 501s...the c2200 the mc275, the c41, the c46, the 205 cd player. I own the c46/252 and the c2200/275 plus the cd player. When I tried the amps, I was using the c2200, I found there were differences and of the 3 I did like the 501s the best, But they were not huge, BUT I haven't tried the 501s fronted by the c46 so I don't know.
I have found that I prefer the tube pre with tube amp and ss pre with ss amp...I enjoy both combos and they have their own sound. I have found there can be differences in all equipment, some large some small, so I am always willing to listen. I am not sure you have to do the blind comparisons, I think if you simply listen and trust your ears, thats the way to go (assuming you are not predisposed on something)...Ironically I have not taken home the int amp....maybe I should try that, would be interesting....one thing is for sure I like Mcintosh equipment alot.