DRblackbird just picked one up used for about $300. I'll see if I can get him to post his impressions when installed.
I've still got to get a pipe, racks, rotopax carrier, bash plate, and shorty levers to pay for! I commute 60 miles a day. So Far, even with MT21's the 690 hasn't had ANY headshake. The WR250R, for all it's vaunted smoothness, headshook at about 75. If I ever get out west, and plan to ride the dunes, I may look into it. But until then, I've got more pressing uses for $700.