I currently have a Droid X and am thinking of going with a iPhone 4s. I do a lot of traveling and I have an aftermarket Alpine radio with an iPod/iPhone control. I can dock my iPhone and play mp3's or Pandora and control it with the car stereo. I really like this feature because being able to play Pandora will allow me to drop XM. I also want to use the iPhone as a GPS, so how would the iPhone work being synced to my car radio and using GPS? I also want to be able to receive phone calls as well, so can it handle playing Pandora, running GPS, and taking phone calls? I know the 4s upgraded to the A5 processor so that should help out. I also heard the camera is better (Droid X camera is bad) and the MP3 player is better than the X which is also something I want. My other question is how is the battery life? When it's synced in my car it will be charging, but I do listen up to 90 minutes worth a day of MP3's and Pandora, along with texting, a little online activity and minimal phone calls. Finally this is more Verizon specific, but I currently have an Alltel talk and text plan with Verizon unlimited data. If I buy the phone used I can activate it and still keep my plan in place correct? What if I buy it new and enter a contract? Can I go into a two year agreement and still keep the same terms? Any help would be appreciated.