Originally Posted by JSpira
iDrive is worthwhile because of the improved access it gives you to myriad functionality in the car (setting Personal Profiles, more info on radio, satradio and esp. iPod).
On the E90, iDrive comes with satnav and the CCC. So you get the high version of the computer instead of the low version, which in addition to the obvious satnav functionality gives you hundreds of voice commands with which to control the carīs functions plus speech-to-text capability for use in placing calls.
It has its limitations, as I am sure you are aware, but like JSpira said, having the improved access to a lot of car features is really nice. The one thing I dislike about the navigation is the fact that you can't enter in POI; drilling down categories is a bitch and time consuming if you don't know where Navteq put the place you want to go to.