In answer to your first question, it's not fair to compare the ride quality of the Dahon's vs the Bike Fridays.
Dahons are great values but they cannot compare to a Bike Friday for ride. The BF are stiffer and have a much more solid feel. Another problem I have with Dahon's is the frames are one size fits all. I'm only 5'7" tall and while the Boardwalk fits me, I'd prefer a shorter top tube and a long stem. Bike Friday's are all custom built to your measurements so the fit is perfect...

It's harder to tell the ride difference between the Tourist and the Pilot. I'd give the nod to the Pilot because the 451 size wheels feel better to me than the 406 of the Tourist..The trade off is tire availibilty. Very few shops stock 451 tires so when I tour I'll take the Tourist because I can get tires/tubes anywhere I travel.

I went with the Pilot instead of the PR or PRP for a couple of reasons. I really like the easy pack seatmast of the Pilot and Tourist. I can undo the quick release and remove the whole seatmast assembly. It is much easier to pack in the suitcase vs the folding mast of the PR or PRP. I also believe the Pilot is slightly lighter than the Pocket Rocket.

Cost was the main reason for not buying the PRP. I ended up betting a very basic spec'd Pilot for around $1100 becasue I wanted to add my own components. I really wish BF would sell a frame only because I ending up stripping both bikes and adding my own parts. To purchase a basic PRP would have cost at least $500 more. If money was not object, I would probably get the Pocket Rocket Pro.