FYI... my impressions...
1) I bought and installed the Blackberry Music Gateway and was disappointed in the quality of the sound. It was certainly not up to the quality of the direct connection from an iphone 4s. The pros for it were good though; it connected/paired on it's own every time the car was turned on; It allowed phone calls to be handled directly by the car's bluetooth (which I preferred since it used the full speaker setup), and the voice commands for the car all worked seemlessly so it didn't disturb this in the car. Using my iphone's button, I can still use the "voice texting" of the iphone through the car's audio system (i.e. no involvement with the Blackberry unit - which is the way I prefer). HOWEVER, after living with it for a couple of weeks, I found the audio quality just not good enough. I returned it.
2) I bought the Belkin unit, and the music quality is much better. It's hard to tell the difference between the bluetooth connection and the wired connection. I've kept this unit due to the sound quality. There are a couple of Cons on the Belkin unit though. It doesn't pair automatically with the car being turned on. This hasn't bothered me, since it's a simple press of the button to pair it. The handling of voice commands in the car are indepedent - which is good. The volume on the head unit needs to be turned up higher through the Aux connection than through the normal radio/CD etc. This can cause some volume problems when switching. The only real problem I have with the Belkin unit is that when paired, it takes over from the iphone's voice control. If you use the Belkin "button" to command the iphone, it plays at a really high volume and is really distorted. It's really made the Belkin un-useable for "voice texting". My workaround, (and it's worked well now that I've become accustomed to it) is to "disconnect" the Belkin unit (by pressing it for a few seconds) and revert back to the normal car's operation with the iphone. After I'm done, I just power the Belkin unit back on by pressing it, and it's back to playing music nicely again. One added bonus of the Belkin unit that wasn't on the BB unit, is that when paired, it presents you with a "bing" through the car's audio when you receive messages or emails on the iphone. The BB unit didn't take over these connections when paired, so you could only hear them through the iphone speakers themselves.
Overall, the Belkin unit's my preferred approach due to the music quality. The BB unit had better integration features than the Belkin, but just didn't cut it on audio quality.
Last edited by Jeffcharger; 09-10-2012 at 10:24 AM.