i'm in the same camp. all other things being equal, i'd rather be on a full-size diamond frame bike than a small wheel folder. i prefer the ride of a larger wheel, and a diamond frame doesn't have the hinges and other moving parts of a folding frame that can wear out and cause problems.

BUT, small wheel folders absolutely have their place. for mutli-moders who take the bus or who ride trains that don't allow full-size bikes, a folder can be invaluable. for people who work where full-size bikes aren't allowed indoors, a folder can be invaluable. for people in high-theft areas who squirm at the notion of leaving a bike locked up on the street, a folder can be invaluable. etc.

small wheel folders are extremely versatile, but if that versatility isn't required for a specific ride, i'd rather be on one of my full-size bikes. my 2 cents.