I'm actually aiming to go back to Def / Disco permanent type 4x4. The VCU, IMO has always been a get you out of trouble system, rather than 4 wheel drive. With mine, at least the rear wheels snatch into life and drive you out reasonably effectively. Could be this is just my FL, could be that after nearly five years together, I have the itch to move on!!
Technically a defender or disco is'nt a 4WD !! I'll probably get hung for that But it's not, At least not without some driver intervention anyway. If you were to drive a defender up a snow covered hill without locking the center diff all the engine power would simply spin the wheel with the least grip. This is why LR chose the VCU as it's automatic in operation requiring no input from the driver, it drives the rear wheels when needed and disconnects them when you don't!! Well when it's working that is