I realize this thread is over a year old, but I wanted to note our experience with the Sena R2 helmets.
We have been using these helmets for a bit over two years and just love them. They easily connect to our iPhones via Bluetooth, and easily connect to each other for the intercom system. It really makes our trips more enjoyable. No yelling to hear each other, easy to call out obstacles from the lead rider to the trailing rider. The few times we have went on short rides without using the helmets, we felt lost without them. The only complaint that I have is when I want to listen to music from my iPhone to my helmet, it turns off the intercom system between helmets. I just downloaded the Sena app for my phone and PC and have not looked at the configuration within the apps so this may be something I just have not set up properly yet.
-Jeff