Depends on what kind of road / trails you are riding. Today from my point of view for adventure riding lighter is always better.
Replaced my 990 1.5 years ago with 690 (which is now prepped with Rallyraid tanks and some other goodies to make it suitable for longer trips) and never regretted it.
I really missed my light 690 last summer in Canada, when I gave up my plans of a solo ride on the Transcanada Adventure trail, not only for safety reasons (not a good idea to do it solo) but also because of the weight of the KLR 650, which I used for the trip.
Lighter is better!