Personally I am not too keen on it. I looked at them before. They often come up on eBay or at least used to. I think it is definitely over priced like a Brompton. I have the 4spd Nexus internal hub on another bike and it definitely isn't what I would call the epitome of efficiiency. Mine makes sort of a grinding sound in 4th gear. It isn't bad but it isn't near as nice as my 7 or 8spd Nexus models. The basic bike isn't a folder so you need to get the break-away version. Even then it isn't a super compact package nor is it light weight either.
I do like the belt drive though and the front mechanical disk brake. For the same price and weight you could get a nicely equipped Brompton that has fenders as well and a wider gear range. The 4spd Nexus is about 174% if memory serves me correctly.