Most Compatable phone for 2012 X5 / Coding

I am considering an 2012 X5 Diesel. I was wondering what the members thoughts are on iDrive and what is the most compatable phone - I work for a carrier so I have access to many phones - what is your experience on which phones work best, the phones I have are now are:

Iphone 5
Galaxy SIII
HTC One X+

Any input of some of the neat things you can do with the phones and office functionality? Does SIRI work?

Finally - can someone point me to a good coding resource - ie what is possible with coding and how does it affect warranty?

Thanks so much.

Trying to decide to keep my 2011 Touareg, or go to a X5d or Audi Q5. THe deals are so good on the X5d it is hard to pass up! OK - thanks!