The Parrot switches automatically too. Hands-free operation is actually one of its strong points with voice recognition and TTS ensures that you never have to look at anything. It switches to phone for a phone call, Bluetooth Audio as soon as an A2DP audio sink is established, switches back and resumes after a call, prioritizes and over-rides for GPS directions, etc. In that case above, I started music playback (A2DP) on my phone before leaving and I was operating the source button only because I could no longer hear it at speed and didn't need it, so I was over-riding the default behavior. If the device had paused or stopped, it would have done the same thing (switched back to "Phone" and waited silently), but either way would be manipulating something while riding if you wanted to stop it mid-playback as opposed to just letting something finish. The only way to send the AVRCP "Play/Pause/Stop" signal to the source device is to switch inputs and, if the source does not respond, it will remain on that input, which was a problem when only the iPod app would respond to Play/Pause/Stop. Apple fixed this with iOS4 but a jailbroken app called "Music Controls" fixed it before AND allowed full AVRCP "Next/Previous Track" support. iOS 4.1 finally adds NT/PT as well, but Music Controls is still useful for having things like album art on your lock screen for non-iPod music sources (Pandora Radio, for example).
The only source it doesn't auto-switch to is FM radio. Even with no Bluetooth device connected, it defaults to "Phone" (AKA "Menu") and you have to press source once to get to FM radio. The source button is the only button on the back of the unit so you don't have to feel around for it or remove your hand from the grip. Your thumb isn't involved at all.
Before full AVRCP was added in iOS 4.1, I pretty much never touched the remote while riding. Heck, the iPhone 4's Bluetooth issues have made sure that I've barely done anything since then either.
Anyway, my point is that the remote isn;t needed much. You answer incoming calls with voice commands ("Answer," "Accept," etc). Well, you can press a button on the headset or the remote if you want. The same button will prompt you to speak a name for dialing, but I would rarely place a call. I never read the online manual to see if there was a magic word for placing a call without pressing a button, but even if there isn't, NONE of the other kids have an internal phonebook with voice dialing, Text-to-Speech synthesis, and voice recognition. In fact, it synced my contacts over Bluetooth so I was able to voice dial even with my old iPhone 3G, which had no built-in voice dialing.
The Parrot's biggest drawback is that it is not an intercom. If you both have one, you have to call eachother on your cellphones. At least range is excellent as long as you have cell coverage.
