Recently rented a vehicle from this SixT branch just outside the St-Pierre-des-Corps rail station and had a very good overall experience.
The office is very easy to find. just walk out of the station with the Starbucks to your left and 20 metres or so to your left you will see the orange coloured shop.
Car rental pickup was very quick, service at the desk very sweet and friendly, we had paperwork completed in just a few minutes. You will walk behind the building through an indoor carpark to the bay of SixT vehicles. Car was in very good condition throughout our rental.
Returning the vehicle was just as good experience, again very friendly staff member and fast!
Would gladly rent from SixT again based on this experience.