Found this interesting article on the Touratech USA website where they weighed a range of adventure bikes (although there's one RT in there Cookie) as they would roll out of the owners driveway. Apparently all are fully fuelled, some with panniers fitted and a few fully loaded for adv riding. For example, Lisa's RTW F650GS comes in at a whopping 310kg!
Interestng even though they weighed some unusual and non current models they did not have a Xchallenge G650x?
After picking my X up in a recent ride into Cape Arid I am still convinced that total weight is critical.