Very happy with my Tern Link C7. One point you may want to also consider: Warranty. I believe Downtube is very limited with such, Dahon had (Don't know if still) quite the trouble with honoring warranty and part replacement, Only communication via email. I'm sure with a quick Google search you can find a number of these stories.
I feel that Dahon is a little overpriced for what you actually get, more so buying the name.
I would also go with handbrakes. I agree with Dynocoaster, the coaster brake does seem to prohibit the revolution of the wheel to an extent, as to where handbrakes allow the rear wheel to be "freewheel". I feel that with commuting in fair distance with a possiblity of a long days work, The less pedaling the better.
Since you live in Manhattan, my first recommendation would be to get an idea of what feels right by taking advantage of a local folding bicycle retailer that carries the mother-load:
To compare Dahon and Tern.
I purchased my Link C7 through thorusa.com and was very pleased, his warranty sold me: http://www.thorusa.com/warranty.htm