Dolmen Hotel
The only reason we picked this four-star hotel to stay was its location: it was one block and a half away from our work base. I did not make any further research before that and did not read any reviews before booking. Once I arrived I liked it overall, especially for the very helpful staff, but found it expensive for what it offered (it was US$100 with taxes for a single or double, and it was supposed to be a corporate rate). If you are on a business trip, you need to hang around downtown and are paid a per diem to stay, then this is your choice. But I am afraid there are better options out there than this one.
Unique Quality: Summarizing, my conclusions are:
Pros: Great location in downtown, near Plaza de Mayo, Obelisco and Florida Avenue. Great breakfast buffet in the morning, clean place, great and kind housekeepers, helpful staff.
Cons: Making the reservation was a total hassle. They do not reply to the emails, they do not reply to the faxes you send, and they make a confusion of bookings, so you are never certain if your booking is still there. One person of our group received a booking confirmation but of another person! I was asked like three times to reconfirm my booking by providing a credit card. I provided the number by phone, because I never provide credit card details by email, but seems they did not write it down in my reservation. Those emails asking for reconfirmation were the only ones I ever got from them.