I wanted the dbl din since the stock radio was a double din. I didn't want to have to deal with getting the single din install kit.
I can tell you off the bat that this is a very nice stereo. The wife and I went to best buy with our ipod touch and the usb charger and tested it at the store. Controls are very responsive, it has a search function which includes artist, genre, song etc etc. It also shows album art on screen. The best part is, it has a button that will relinquish control back to the ipod and still play the music making for easier navigation if you want it.
I did have a sirius subscription, which could be set up with this unit (with the satellite accessory) but I am opting out of the pay radio game. Besides, the exclusive content is what I wanted anyway and I know how to get that.
The only thing I wish it had was a nav system. But I have a tomtom for that and it would cost a heck of a lot more to have that included.