Reserved a premium, which would've gotten you either a BMW 3 series, a Mercedes C class, or an Alfa Romeo. Wished had gotten the 3 series, but the C 180 wagon was a good alternative. I'm surprised the trunk couldn't hold more than 2 big luggages and 2 carry ons. That's the same as a VW Polo that we hired in Napoli and a Ford C-Max we hired in Milan 2 years ago. We got a Peugeot 308 wagon later in the week and that car can swallow 2 luggages and 3 carry ons plus 2 backpacks.
The car is surprisingly cramped. I'm only 5 11', but after a 3 hour drive my legs felt tired, especially the right one.
I do like the cruise control, that feature is very useful in Switzerland where you have to watch your speed.
All in all, very satisfied with Sixt. Very good selections of good, interesting cars and they present everything upfront without hiding anything.