Depends on your definition and expectations offroad, along with your skill level. Someone with many years of experience offroad and advanced skills can ride the 690 many places some one with less experience will struggle, get exhausted.
It's not just the weight, but the power of the bike that takes more energy and skill to ride, offroad. That is just as, if not more of a factor than the weight offroad.
I've ridden the 690 in the desert and black diamond single track here at home in NorCal. I thought it was just fine, hid its weight well, certainly no dirtbike... but doable. Others with less experience simply could not.... and I was riding their bike out.
If you don't have that experience, you are going to struggle to gain it on the 690 and could be miserable. If you have dreams of riding single track and gaining dirtbike skills, it's not the right bike. If you already have those skills, it might be a great choice.
Just my opinion and experience.