Good.

Alamo often offers discounted upgrades during the off-season. Their service is excellent.

Very good service, the car rental office was a little tricky to find at first as they had moved to a new office around the corner. The car was spacious and a good spec, it was a smooth process on collection and return just be careful of the ztl zones.

Great

Like: The service at the rental office was friendly and very good. We were a large group of 5 adults and 4 children, who had booked 2 station wagons. The lady at the pick-up office saw our luggage (which we considered typical for US / Canadian families) and pointed out, correctly, that it would not fit into the cars we had booked, along with the passengers. I guess North American ideas of "medium" sized cars is different from European ones. She offered 1 car as booked, and offered a 9 seater mini-van instead of the 2nd car. The additional charge was very reasonable (80 Euros for 5 days) and the swap made so much sense for us in the end. Very good service, and all was handled with the least amount of fuss or hassles.
Dislike: At the time of drop-off, I did pay a steep fee (45 Euros) for not refilling the gas to full. This fee was in addition to the cost of the fuel, which was also charged at a premium. I suggest that you should leave enough time to get a refill before returning the car to avoid this.