that mod the braniac all in i think its shy of £700 with customs. Plus if you dont have a "non navigation model you need to buy the base switches from Ebay and mess around with controls. Steering wheel controls too. The android retrofit just for the part plus shipping i saw was £699 off Ebay from Australia.
Depends if keeping the car. Each to their own. Braniac looks neat but android/raspberry retrofit is a better option as our center console is 90 degree not slanted up like many modern high end cars. So if youre tall youd be cracking your neck to just to take a look.
You do get a much more modern interior look though. As long as you can change the track/folder, make a phone call and still have voice recognition from the wheel then its not so bad. This is mainly functionality over looks. Id prefer retrofit.