I sold an 07 GSXR to buy it and the transition caught me by surprise. I found the SD difficult to ride smoothly at first, and spent a lot of time on the board looking at solutions for "throttle snatch". Eventually I came across a tip from a board member to place a finger on the front brake to steady my throttle hand and with a bit of practice the snatch disappeared. Friends who have never ridden it before often have the same problem, but the the fueling is very good and the snatch disappears once you take out unwanted throttle inputs.
One of the reasons I bought the bike was to be able to have fun at nearer legal speeds. The SD is not very fast, but the handling and brakes are superb and it's a real blast to ride down a winding country road. It even tours. Last August I did 2,500 in 8 days with the Yamaha FZ1 Owners Association up the north CA coast , over the mountains and into Nevada. The seat was fine for my skinny ass, and the "touring" wind screen saved me from getting a crick in my neck.
If I were going out to buy a bike right now, I would buy another Super Duke. I'm planning on keeping it for quite a while yet, and hoping I can get some track time on it in 2009. Any US West Coast owners doing track days in 2009 ??