I think you will find that no folding Dahon will keep up with the pocket rocket. The bike friday's frame is MUCH more ridgid and therefore more efficient. The stem arrangement is also a source of flex in the dahon that is not present with a bike friday. The 451 wheels will give lower rolling resistance, especially on mixed surfaces. I would avoid any hub gear arrangements if looking for all-out speed: they can consume up to 30 watts of your output.
I found that the new world tourist was 2-3mph faster than the speed pro on my daily commute (both had 3x8 arrangements). I would therefore suggest that you go for bike friday if speed is your main concern.
You may however find the lighter dahons are better climbers due to much reduced wheel weight.
The 2005 dahons are said to be stiffer in the frame and at the handlebar.