Rode both bikes at the weekend back to back,I have a Tuono R mate has a SD.
The T is far more planted in corners,far more grunt,and seems to handle a lot better,it also has more power.
The SD is a fine bike,much higher seating position with lower pegs,a lot of fun to ride with it's power further up the rev range,although I think the front is a bit twitchy.
Would I swap my T for a SD,never in a million years,my mate also said my bike was a far better bike than his :thumbup