Ui6 is a older model, and pre-dates the Metro. Ui6 speed will top out around 23 mph. The display is not as nice as on the Metro, and there is not as much power coming from the motor, in part limited by the controller sizing they chose. And it does have mechanical brakes instead of hydraulic. Also it only has 7 speeds, and the lower tier shimano derailleur (Altus), than whats on the Metro. Metro is 8 speeds (Acera). There are no suspension pre-load adjustments available on the Ui-6. There is on the Metro.