The Brompton and Dahon Curl folds small. Both have itty bitty wheels. So you don't need to carry them, unless going up the stairs. If you have to take the bus/train a lot, then the Brompton or Dahon Curl is better. The Pakit is lighter I think. Also uses standard components. Maybe Linberl can chime in. Another option is the Dahoneezz, small bike but no itty bitty wheel. So you have to carry.