Sorry if this has been discussed before, should have searched first!
Will do better next time!
With the proNav option, although the second binnacle on the dash is there primarily for the satnav, it also has functionality for the PDC and Bluetooth options and also is a better display for the radio etc, so it is not just for the navigation system. It also makes the car more 'complete' in my view. it is down to whether it is worth the £2K, but it seems makes a big difference at resale and £750-£1000 is not to be sniffed at!