The cool thing about "flipping the switch" on the FR or PR is that there is no interruption in sound. There is no click, pop, etc. OK, you can hear the mechanical sound of the switch flipping, but even that is not loud. It's really strange to just flip the switch and hear a different IEM! The switches are very easy to switch while you have the IEM's in your ears. I find that being able to switch so quickly really reveals the differences. Compared to what we have to do now: remove IEMs/headphones, unplug cable, plug in new cable, put in/on new IEM's or headphones; flipping the switch really shows the difference in sound signature. (Just don't forget to switch both switches the same way! Otherwise the sound is really weird with a different IEM in each ear...)
Very interesting and VERY cool feature.
When are we going to get a 3 or 4 way switch? I want to have the whole Noble line in my ears at once and be able to switch between them!