That is really some lovely work.
I'd probably say the "flow on the tail" issue is related to the "Swoop" line mentioned here:
http://www.bikeexif.com/build-cafe-racer - the back just looks a bit high - I don't think it is the upholstery.
I am definitely on the outside here, but I just don't think the looks are all that great. It isn't terribly different than an S2000 crossed with a 370z or something like that. As far as looks go, it has nothing on the Maserati Gran Turismo for example.
Ryca does one for the Sportster, but I don't think it is as successful visually. Even the CS-1 needs its front wheel tucked in a bit more...Eventually I will end up doing something that is in a more modern vein a la Holographic Hammer's concept stuff:
Frankly I'd only get a cab. I am never going to track the thing. And having a convertible is about 10x more enjoyable for me than 150% more stiffness or whatever. And, frankly, talking to another Turbo owner here in my building, he regrets not getting a cab since it is easier to put your kids in car seats in the back over the side with the top down.
Yeah, I am not necessarily looking for that level right now. I am actually thinking right now of doing a Ryca CS-1 as a little cruiser around town with a bit of additional customization. I'd do it myself, but I would undoubtedly end up with a half-finished bike in my garage.