I did a 7 day credit card tour in Normandy last year, averaging 25 miles a day on a Dahon speed tr. It is designed for touring, but quite heavy. My Dad was on a Dawes galaxy, and I managed to keep up with him, just. He was 77 I was 52. The other custom design small wheel tourer I have seen on this forum is the New World Tourist from BF (Bike Friday). Advantages is that if you need to hop on a train or fold the bike in your tent it is more doable. Luggage wise I don't know - I fitted normal panniers, I think though, stuff on top of that - tents, for example, become more of a burden. I wonder about small wheel bikes longlastingness in comparison to a good full size tourer, but haven't seen any data or claims. Also, I think some parts are less common, and so if the bike breaks in say Mexico it may be bigger trouble... There are some reports on the folders forum, most recently from "Lucille" who did 3 weeks in France.