[Mav]

Easier is subjective... But the R12 has a lower centre of gravity and a 19 inch wheel, I think it also has a lower seat height. So even tho it's heavier, once you're moving it can feel more capable on the road.

But if you want to play offroad, the 8GS is a bunch of fun, while still being very capable on the road.

Why do you ask: "Which is easier?" I think you would be better served asking which bike better serves your needs, because they're both pretty easy to ride.