Having just bought one on 10/28/09 I can tell you personally what I think about the Kustom Kruiser Double Down. If you are the type of person that gets a rush out of being noticed on your bike (I think most of us on this site are) then this bike is definitely for you. It is the coolest looking bike that I have ever seen in person bar none! This thing stops people in thier tracks and they just stare or point or both.
Unfortunately it is not the most practical bike to ride. The design of the bike is so that you are sitting really low and the postion of the pedals are not far enough in front of any rider that is 5'7" (may be 5'6") tall to get a steady rotation of the crank. If you want a bike that looks really cool while you commute long distances with it then this bike is not for you. If you are just taking a slow cruise down the boardwalk or cruising slow around the nieghborhood for a second (again not very good for long distance riding if you are just average height, this is a bike for shorter people) or just like me willing to put up with it's short comings because of the bike's cool factor then this bike is for you.
One thing that is annoying about this bike is that it shifts out of the gear you put it in too easily. You have to be mindful of the shifter when you have to grip it tight or you will find yourself constantly accidentally shifting the bike out of the desired gear. Also the rear fender on my bike rubs the rear tire slightly. I can deal with it but I would of course perfer not to. The bike it suprisingly light, I can easily lift it with one hand. I guess that is due to the Aluminum frame and fiberglass tank and rear fender.
Another issue with this bike is that the front disc brake is not independent from the supension fork. When you hit the front brake lever this causes the front end to slightly bounce or dip. This is not a real big problem for me though. The crank on the bike is a really cool looking chromed out three piece.
The ride itself is a smooth cruising kind of ride so much to the point you will not forget it's a cruiser bike definitely made for just that. I just wish that it was designed better to accommodate adult riders (average height and up) like it was intended to do. I guess it's like it's an adult chopper that you ride like a BMX bike (meaning that you can easily stand up on it and ride in the standing position). So if you had sitting on your a** mind while you cruise then once again this bike is not for you as you will encounter situations that it's just better for you stand up on the bike instead of sitting.
All in all If I knew then what I know now about the bike I probably would not have bought it but bought the Phat Cycles XR-3 like I started to do. Instead I got cheap and bought the KKDD. Like I said though as far as mass produced bikes go, in my opinion, this bike is the champion of cool.