I had a friend over last night and we did an a/b comparison of the Merlins with and without the RC network. We started with it on, and they sounded great, and we were both fully prepared for there to be little or no noticeable difference when we took them off, but we were both struck hard by the difference. Without the RC network, vocals had a little more air, there was more separation of sounds and instruments, particularly in complex passages with a lot going on, but the biggest difference was a significant increase in the bass.
I would highly recommend that all Merlin owners try their speakers with and without the RC network, but particularly those who have amps that terminate with a Zobel network. The difference was far more than I expected, and the speakers now sound even more amazing than they did before!