I did about 100 miles over the weekend on my naked Scout with the SRL-EXT in an RF-1400. I think Frank White sums it up nice about the overall quality of sound. I really think the overall experience is highly dependent on helmet, fit of helmet and placement of headphones over and to the ear, as well as, quietness of helmet. I have no experience for comparison with other comm systems.
My experience of listening to music and phone calls sitting in my house was significantly different than on the bike. Something is lost in overall quality of sound when on the bike while volume is more than adequate (for me). Why that is will take some troubleshooting. It could be as simple as the placement of the headphones in proximity to the ear was different sitting in my recliner compared to riding on the bike. Perhaps it has something to do with the noise cancelling feature filtering out some of the frequencies giving depth to music as the ambient sound pressures increase. Again, volume is more than adequate as I found myself turning it down. It was the depth of music that was altered (using Apple Music app). I will say the difference was negligible with phone calls which made me think it has more to do with noise cancelling, filtering out certain frequencies. If so, that could mean that ones' experience could be drastically effected by the type of bike they are riding (fairing, windshield, naked, exhaust, etc.).
I talked over 30 minutes while on the bike and the experience was crisp and clear at 50-60% volume. The person I was talking to said that I sounded like I was just on my phone and could not hear the bike or wind noise with the face shield shut. That was up to 75mph. With the face shield open, they could still hear me fine but with whistiling from the face shield which I was hearing too. More bike noise (likely exhaust) was heard when slowing to stop, downshifting or accelerating in the lower gears but it was not distracting to them and if they didn't know I was on a bike, they wouldn't know the source or pay attention to the background noise. I talked with two people and neither of them could hear any bike or wind noise at higher speeds with my voice being clear as if I was just talking on my phone.
Before my next ride, I plan to make some adjustments to the headphone placement and am even going to try it with the Surefire EP3 earplugs with the filter cap open. I did not try the intercom mesh features or FM radio. Overall, I'm pleased and would install the system just for the hands-free phone features. For those of you that own multiple bikes in different configurations, I would be very interested in a side by side comparison of the system using the same helmet to see if the depth of music changes according to the mic's interaction with environmental noise. I guess a better way of doing this may just be to unplug the mic assuming of course that the noise cancellation features are working for the headphones, as well as, what is being transmitted.