Generally SIXT at Bordeaux were great to deal with - there was only a short queue, staff were very friendly, office was easy to find (just outside terminal), rental was a great price and there was lots of choice on vehicles. However, a couple of things to be aware of:
The first car offered to me was so dirty (windscreen in particular covered in dirt) I had to refuse it. The second car was cleaner, but damaged on every single panel, which whilst I could live with, most was NOT reported on their damage system. Therefore I had to then take additional time to report scratch by scratch to avoid being charged. This took additional time which was not ideal.
On return of the vehicle, I ensured the clerk was shown and checked the car and damage over with me and told "no problem" - however, I still received emails from SIXT asking me to clarify why I returned the car with additional damage....but thankfully this was quickly resolved by email.
I would still certainly recommend SIXT at Bordeaux (other hire companies here have terrible reviews), but I would strongly advise you check the 'damage report' email that they sent to you and take lots of photos of the car BEFORE you drive away and ensure everything is noted down - allow suitable time to do this, otherwise you could end up with a big bill for something you haven't caused. Also consider taking your own hire car excess insurance too.