We stayed at Hotel Lyon and found it much as others have described it--we had a large, clean suite with a nice bathroom (plenty of hot water) and a good breakfast, all for a very reasonable price. If you're looking for fine furnishings, this isn't the place, but it's well located if you want to walk to shopping or restaurants and the hotel staff are very helpful.

We spent the month of October / 2008 in Argentina. Our first 6 days where spent at the Hotel Lyon. We also spent 3 days there at the end of our trip.
We do not speak Spanish. There was usually someone there who could speak English. This was never a problem. The staff where all excellent.One evening my wife had her purse stolen at a restaurant.We returned to the hotel to use the computer and phone. The staff where most helpful and kind .
Upon our return at the end of the month we where welcomed and made to feel at home, again, great staff.
The hotel is not new. But very clean and handy to the micro centre.
We walked a large area of Buenos Aires, and this hotel was convenient to return to by cab from anywhere.
Its also handy to any services you would want.

we spent 10 days in Buenos Aires at the Hotel Lyon. We loved it from the beginning, it is old, classy and full of character. We stayed in an apartment type room with 2 bedrooms, a sitting/dining room and large balcony. The rooms were very spacious & clean, with a fridge, and a powerful shower with plenty hot water. The staff were very helpful, friendly and professional. We left our suitcases here while we travelled to the Iguazu falls. We availed of the laundry service available to the hotel. The breakfast was coffee/tea, croissants and juice which was nice. There was free internet, and a nice foyer with leather sofas. The location is good, about 20 mins walk to santa Fe, and the Olilisk on avenue 9 julio, but a very easy walk past nice cafes, icecream parlours and shops. Great restaurant around the corner called Chiquilin. Would stay here again if I returned to BA. Great value.

We chose the Hotel Lyon because we were traveling as a larger family group and needed a larger suite at a reasonable price. The suite was a very large three room suite with a large bathroom which included a large bathtub/shower combination. The decor is very old, nothing glamourous or fancy, but everything was very clean and comfortable. The hotel website photos were accurate.
The hotel staff was friendly and helpful. They provided good suggestions for tours and restaurants and, when a light bulb burned out in the bathroom, they replaced it immediately.
The hotel is conveniently located for walking to restaurants, the subte and other microcenter sites.
The hotel was, for the most part, quiet and we felt safe. There was some renovation construction noise in rooms near ours during the day but we were not in our room much at that time. The breakfast is average. It was very cold in BA while we were there and the rooms were heated nicely at night by a radiator controlled by the hotel, not the guest.
I would stay there again if traveling with a group where we need to be able to spread out and not spend too much.