I have an iPhone 3G and I was looking at getting the TomTom car kit when its released plus the TomTom app. How does an iPhone 3G + TomTom app + TomTom car kit match vs a TomTom GO 720/730?

I've been told that the call quality on the TomTom 720 or 730 and similar models is not the best compared with dedicated bluetooth units. I don't have the TomTom app yet. A GO 720/730 will cost me more but I don't mind if it performs better.

The other thing I could do is get a TomTom One instead + a Parrot Minikit which I can get for free but that would mean 3 devices to charge if needed.

I appreciate any suggestions