ToTo Man
the band not the dog
A valid comparison would be to place the other pair on a directly coupled stand the same height as the isoacoustics stand.
We agree on something for once. I maintained equal heights for my comparison with and without the OREA pucks. There were small measured changes in the FR and waterfall, but no more statistically significant IMO than the small variations you already get when you repeat tests within a few seconds of each other, which supports my opinion that REW and/or the act of undertaking acoustical analysis in a typical domestic environment is not accurate enough to detect and attribute subtle changes.
Also, looking at distortion plots below approx 50Hz is absolutely useless unless you live in the middle of nowhere. If you have a road or railway line within a few hundred meters of you, like I do, or live in a place where it's often windy (which is pretty much anywhere in the UK!), you haven't a hope in hell of being able to take accurate and consistent low frequency distortion measurements.
@JTC - Using OREA pucks under my Celestions without a doubt makes them more forward and dynamic sounding, especially in the upper-midrange / lower treble. Without the pucks I usually run with a -1.5dB cut around 5kHz but with the pucks I need to increase this to -2.5dB to maintain a comparable tonal balance. Well worth it though for the improvements elsewhere, especially in imaging/soundstaging.