Worth the extra $$$ and weight? - probably not. Leaving an expensive bike in NY is asking for it to be stolen in the street or from wherever you live. No lock can resist power tools, and now power tools are battery operated. So you might as well give up on the idea of chaining an expensive bike to a pole and leaving it unattended for long periods of time. See the piles of posts for security ideas.
2000 Montague CX, I do not recommend it, but still ride it.
Strida 3, I recommend it for rides < 10mi wo steep hills.
2006 Rowbike 720 Sport, I recommend it as an exercise bike.
1996 Birdy, Recommend.
Wieleder CARiBIKE (folding), decent frame.