A side note about the Cardo Scala Rider Q2: The Q2 doesn't support A2DP, so these features won't work. There's an app in the market that allows you to pipe all audio out to bluetooth, but I never tried it. The voice dial feature is now available in Android 2.2 FroYo on the Evo (the latest OTA update).
I recently ditched mine for the G4, and the improvement was unbelievable. My girlfriend and I both use the new G4s and they work amazingly. Using the Evo, we get bluetooth music (A2DP), navigation, phone calls, notifications, status updates, EVERYTHING. Needless to say that when my G4 is connected, my phone READS my text messages. I use Tasker and SayMyName Dessert to do this, and I have it automatically turn on Bluetooth when I dock it, and load Pandora when bluetooth is connected. Tasker is truly probably the best $6 I've ever spent in my life.
But yeah, the Scala Rider Q2 was horrible. All I was able to use it for was phone calls, intercom, and FM radio. It didn't have a boost for the MP3 jack (had to use an external "boosteroo"), which made listening to MP3 players nearly impossible. I bought my Q2 Multiset for $160, then turned around and spent another $240 on a G4 Powerset. The G4 units were brand new...I still don't know why the guy sold them to me so cheap
I almost feel bad because the receipt in the box said that he paid $537 (after tax) for them back at the end of March 2010. But after all, to me, the G4 Powerset is really worth the $500 that they retail for, just saying...
We haven't really tried the intercom on the G4s yet, but they supposedly have a 1 mile radius. And they don't cut music when you cough!! It just beeps and continues to play music until it connects in intercom mode.
But yeah, Evo + Tasker + Motorcycle Dock + Cardo Scala Rider G4 = pure lust. I wouldn't have it any other way!