Fender B. I'm in the same boat as you and I have narrowed down to ios s9 and eclipse p9 as well. I test rode the 20" vector p8 and 24" node d8 at the local store. 24" definitely gave me a more solid feel when I went over the bumps. I did a lot of research on the the 2013 black orange spec. Even on Dahon website there are 2 version. 2 different weight. one seems to have the seat post bump.
V1:DAHON Bikes ??:*Ios S9*
V2:DAHON Bikes ??:*Ios S9*
The only thing I like about the 2014 black gold ios s9 is the light weight 21lb, the 2013 version are a lot heavier.
I like the eclipse p9 as well. The build quality seems better and there are more add ons. P9 feels more like a commuter bike then a speed bike. But I really like the white/red color. In my area they still have some p9 left with tax the price is the same as 2013 ios s9.
I still can't decide, and not sure if it helps, just sharing my thoughts good luck