I considered the f800 a very agile great bike in the dirt but lacks power for me on road - when I rode the f800 back to back with the 1200 on road it was like night and day. What I am after is great power for on road but the ability to take the bike through the bush and outback to do some exploring off the beaten track - range is therefore important hence the adventure but fuel cells and the 20litre tank will suffice.
For offroad and really crappy trails I have got a dirt bike - there's no way I would want to lug the 1200 down some wet clay rutted trails no matter how many electronic gizmos it has !