Okay, I'm also researching units.

The less expensive ones at BestBuy and SavingsLot are the VM9312 model.

The model originally recommended is the VM9512HD

On the questions of NAV101 or NAV102. It is a separately purchased accessory required by the VM9312 and VM9512HD in order to add Navigation to the units. Currently I've seen the NAV101 for about $250. I have not seen the NAV102 for sale yet.

KFrom what I understand the Kendwood has a much more sophisticated Navigation unit, but it is about a $400 add-on. So, the Kenwood works out to about double the price.

Tough decisions. None of them, though, mention iPhone 3G compatability or Sirius television.