Does the MFD2 have a built in 6 disc changer or do you mean the armrest changer? I have the ipod adaptor in there at the moment and despite its limitations would probably keep that with the MFD2.
I appreciate what your saying about the crap sat nav but to be honest I'm only changing it for a bit of dashboard bling, and better sound quality? I've managed the last three years without sat nav so anything will be an improvement!