advrider.com has your answer.
I've got a Triumph Tiger 800xc, does the big K's, good in the sand if you keep the pace up. I've found the 600+ singles great for the track once you're there, but a PITA doing distance. Horses for courses, a bit like CT's I suppose!
Back to the original post: Yamaha XTZ660, heavy, underpowered, very tall in the seat, expensive. Nice standard suspension, brakes, luggage attachment points, pretty bike.
Nephew has a XT660, and it's not that much lighter than the Triumph.
Anyway, in the overall scheme of things, it doesn't matter a rats, just as long as you get out there and ride.