Dahons are definitely not awful. Except don't get me started on the handlepost hinge - IMHO they are awful, but with savvy that can be solved. Dahons have a bit of torsional flex ie side-side movement of handlebars wrt saddle, but most folding bikes have this to some degree. There are some notable exceptions, the Swift being one, Birdy another. My first recommendation if you want an excellent fold would always be Birdy, but you need a good wad of cash.
You can order a Swift with a Nexus from Peter Reich, he builds custom Swifts all the time for remarkably little extra. (I know you have said you would need a smaller fold, but still...)