BMW 1300GS Adventure vs. BMW 1250 GSA Stick or Twist? What would you do?

Test Ride of the new BMW 1300GSA, cost to change from a 22 plate BMW 1250GSA loaded with accesories/upgrades and a quick review of my GS/GSA range of bikes since 2008. Do I stick or do I twist and make the leap to the 1300. What would you do?