I ended up buying a 2015 one, which was described as one of the best laptops ever in reviews [1]. Plus, I got a slightly used one for a good price (waiting for it to ship).
I'm pretty sure I'll get many years of happy usage out of it (it replaces a 7 year old Mac mini, althought I did upgrade memory/ SSD on that one).
The only thing I may end up missing is the touch bar, which does not get much love here, but could turn out useful. Do you develop stuff that needs to support touch bar? Then obviously get a new one...
Btw, do add "Ask HN " to the title.
[1] http://www.macworld.co.uk/review/mac-laptops/apple-13in-reti...