The Zurich airport rental office is not far from the arrival hall, and you can walk there without needing a shuttle. There were not many people in line, and while the staff was not particularly enthusiastic, they were polite enough. I got the car quickly. However, the return location at Geneva airport lacks clear signage. Initially, I couldn't find the return spot and had to circle around and ask someone for directions. If you miss the only small sign, you might end up driving into France! Of course, this is not the fault of the rental office, and the return process was quick.