We stayed in the Rochester for 3 nights on our first venture to Buenos Aires. The hotel is very nice, with clean rooms and good bathrooms. As well as this, they were very reasonably priced. The main negatives are the staff, who are generally unhappy,don't really smile or say good morning, as well as this they are not proactive within promoting the many tourist attractions of BA. The Rochester is a nice hotel if you planning a short stay and know where you are going and what you want to do.
Unfortunately, you will have to pay for the use of WiFi in this hotel. In this day and age, I really don't think that customers should have to do this. Lastly, bare in mind that you can get an all round better deal elsewhere, a hotel with free WiFi and breakfast. We checked out after our 3 night stay, not unhappy, just thinking we could get a better deal elsewhere. We chose to stay in a hotel nearby in the Recoleta area. It was the same price, with free WiFi, buffet breakfast and very helpful staff.