Just wanted to update with our Sixt experience! The shuttle arrived fairly quickly to the airport, and it was a really short ride there. It took about 30 minutes total to get our car once we got there. The holdup was that there were two couples that had issues with their reservations, so two of the agents were tied up with them. Once I got to a free agent, I gave them my car insurance info, driver's license, and they assigned my car. Very quick! The car was very nice (Toyota Camry) and clean. When we returned the car, we didn't have directions back from them, but put the return address info into my phone, and the directions were pretty clear. Took about 5 minutes total to return the car, and the shuttle bus waited for us. Dropped us off in the right place and we were set to go! Pretty seamless transaction, and as long as the prices stay right, we'll probably rent from them again. They would need to have competitive prices to lure people away from the rental agencies with presence at the airport, but all in all, pretty good!