axolotl, I see that you've gotten a lot of responses here on this, so I hope I'm not duplicating anybody's post, but hopefully I'm not, my sister has a Dahon and a bike friday tandem. She rides both and loves both!!. She bought the Friday befor the dahon, but they are for two different purposes. I can't remember the kind of dahon she has but it's silver and she got it this year, she's had really good expierences with it along with her BF also. So I think you'll be just fine if you get or have both!!
Benjamin