I have been in both cars, and the US car is better quality. The fit and finish of the dash components is way better on the US cars, the doors close much better, the interior materials are nicer, the seats are vastly better, and the US car has better mapping for the ESC and TA.
I would still prefer the German version and here is why.
The EU gearbox is designed for performance and not economy, so the ratios are very close together. The US version has gearing that allows for lower revs in 3rd and 5th, resulting in gaps that I am sure I won't like.
The steering wheel is better looking and the smaller rim is easier to grip with my smaller hands. The EU car also has volume control on the steering wheel, and the US does not have that feature.
The headlights and front bumper of the EU car are works of art! The projector lights with city lights look very upscale and the headlights function outstanding. The US headlights don't look as good with the silly reflector, and no projectors offered. The US bumper cover is my least favorite part of the car, and its my favorite on the EU version. I don't care for the lack of fog lamps and the smaller air intakes. Hands down, the EU version of the Fiesta is better looking.
The EU version has a rear mounted fog lamp that I am big fan of.
You can get factory 17" wheels with summer tires from the factory, and the wheels don't have the TPMS system.
The EU Fiesta runs on 93+ octane fuel, which I prefer.
I would pay a few extra thousand dollars to have the German Fiesta, even with the faults with the interior. The exterior and gearbox more than make up for the seats, gaps, and interior materials.