At first glance I liked it but really its way way expensive and the original S40 is a lame bike to start with. You could do better if you just cafe any old twin. I found another article ;
You give them your bike and they cafe it for $5500. They state that the S40 is available for $8,000. So for $13,500 you get a single cylinder bike that can probably top out at mabe 80 mph.
I was a huge fan of the MAC bikes based on the Buell Blast motor - until I saw the $10k+ price tag. This looks like a hell of a lot better attempt at that idea - Those bikes are unchanged in the last decade and a quick ebay search shows a dozen out there for between 2000-3500...so this can be done for about $6k - which is a little more reasonable...