Jipe, thanks a lot for your detailed reply! You're right about deciding on needs first; I should have divided my list into two categories, since I'm actually having a hard time deciding between a small-wheeled, highly portable bike and a full-size bike that folds for storage. I think it really comes down to how limiting the smaller, better-folding bikes are in terms of ride quality/distance, vs. how annoying the full-size ones are to fold/roll/travel with. There won't be much need to quickly fold the bike to hop on a train or anything like that, but I'm trying to imagine what someone would do with a bulky, hard-to-roll bike after entering a store, for example. Locking it outside would seem to defeat half the purpose of a folding bike.

I was already leaning toward the Birdy and the Change Bike (now even more so after reading your reply), since the Brompton seems to be the least comfortable and I'm already having a hard enough time finding the Joey, let alone thinking about wheel replacement.

Could you or anyone who's ridden/owned a Change Bike weigh in on just how unwieldy it is when folded? I've read pinholecam's excellent posts on the Change Bike, but still don't have a good idea of whether it would be a pain to lug around without a car.

The Birdy is quite appealing to me, but I'm struggling a bit with the price -- would love to be convinced, though!

Thanks again!