Stayed here twice in the course of a five day trip to Spain. While the hotel is not in city center, it is in a pleasant, safe residential neighborhood 1-1/2 short blocks from the metro. It is also a very brief, 10 Euro taxi ride from Atocha station. The Prado, Thyssen, and Sofia are a 20 minute walk through Retiro park. It is also a short walk up a gentle slope to an area of town with many restaurants. Rooms are adequate, large comfortable beds, clean, towel warmer in the shower, adequate bathroom supplies, etc.
Cons are primarily the lack of any way to tell time in the room (no clock at all), the fact that the lobby is a flight of steps up from the street (no ramp for luggage that I saw) and the odd internet system that requires logging in with a password that is sent to a mobile phone. Even then, the wi-fi signal is weak and the provider won't permit downloads or the use of services such as internet phone.

The hotel is a bit off the tourist track but easily accessible by metro from the airport or the city. The hotel is set up in an odd way,with two hotels being in the same building and separated by an odd five minute walk. The hotel itself is very clean, has a convenient bar area, and is quite efficient. The rooms are also quite clean and modern. Rooms are not loaded with frills but are spacious, comfortable, and have a pretty good sized bathroom. This hotel isn't for someone who needs a load of amenities or a perfectly central location, but for a tourist looking for quality lodging at a reasonable rate,this picky traveler would stay there again.

We live in Madrid, and have been recommending the Ayre Gran Hotel Colon to family and friends for a decade now. It's located in a tree-lined, quiet, safe, residential neighborhood that is an easy walk from Retiro Park, and there is a bus to Puerta del Sol just downhill from the hotel that will get you to the heart of downtown in 15 minutes. There are also six other bus lines and a station serving two Metro (underground) lines within 200 m of the front desk. The hotel was recently renovated inside and out, and the rooms are nice. The times we've booked rooms for people (on the internet) it's been good value for money.

Also, it's just a across from one of Madrid's best public swimming pools, the "Piscina Olímpica" (which even has water slides in summer).

But now there's a problem, as noted in the title: the stench of feral cat urine. Apparently, some women who live near the hotel have in the past year taken to dumping literally bags of cat food on the hotel's property nearly every night, with the result that its gardens (the entire complex is surrounded by gardens) are swarming with an ever-growing colony of feral cats. This has been repeatedly pointed out to the hotel's management by locals, but as far as I know, until now they have yet to take serious action to address the issue.

If not for the feral cat waste, this would definitely merit a Very Good; let's hope someone deals with it soon.

I spent 3 days in this hotel in November 2011.

It's a nice, modern and clean hotel. The staff are friendly. It feels secure. Great prices!

The washroom is very nice, but is about the same size as the living space of the room (we had a twin room).

The one thing was that the hotel location is not quite in the city centre. It would be quite a walk, but there is a subway stop right in front of the hotel, giving easy access to all that Madrid has to offer.