In my case, I didn't have access to testing and measurements. However, I performed one crossover mod on a single speaker, then compared it to the other one for my own personal impressions. Ideally, it would have been better to have a friend determine which speaker to place in the L/R positions while I was out of the room and then when I would return, then note my observations between the two. This would have been more along the lines of a double-blind test. In the case of the modifications, the new resistors were a bit larger than the original sand-cast resistors, so I had to move the crossover to the bottom of the speaker cabinet after de-coupling it from the panel where the binding posts connect.
I have another pair of B6.2 that are currently not modified. The modified version was sold off due to a speaker purge of mine. However, if I decide to keep the current pair of B6.2 speakers, I'm open to ordering the parts, performing the mod and going through some additional observations. What I did note, though, is that the upper frequencies were not quiet as intense following the modification and could experience more comport in listening for longer periods of time. But, now, the Elac Debut Reference is becoming more available and I may opt for a pair, but would sell of the B6.2.
