I spent a lot of time talking to the tire expert at Chaparral Motorsports in San Berdo California, and he said he gets a lot of negative feedback from guys that have tried the D220s. Cupping, strange wear patterns, poor feel after a short time, and poor mileage.
He said his biggest seller is Bridgestone tires. He heard a lot of praise for them over the years, but says to avoid the "U" tire for the rear on the ST1300, get the "F" tire.
He says Dunlop has lost a lot of business to Metzler in the last few years, and believes that the management at Dunlop has made a decision to service Harley and Honda, but has given up on individual customers and their needs and requests.
I have about 11,500 miles on my Bridgestones, and am ready to put on another set. Good rubber.