I used the SMH5 for about a year, and upgraded to the SMH10 which I have now also used for about a year. I have the latest firmware version, and It syncs nicely with my iPhone. I regularly ride with two other guys who both use SMH10s. We are all paired with each other, and use the tap-to-talk method. Sometimes the Senas can be a bit glitchy, but overall I have been very pleased with the performance and the battery life has been great. We have ridden many times for ten hour days and have had no issues with the units keeping a charge even with frequent talking. I upgraded to the larger speakers, and even with my earplugs volume has never been a problem with my Shoei Qwest. I have noticed that if the formation gets spread out, even if I'm much closer to one rider, range can become a problem. I think it has something to do with who the first two riders in the intercom connection were, and the distance between those riders and the rider who joined last. Basically, if you keep the formation relatively tight (no more than 4 second intervals), my experience is that the system works really well.