I stayed for four days at Ibis Buenos Aires, and it was a great experience. The location is great to go walking to the Obelisk, Plaza de Mayo, Santelmo... Subway stations are mostly 2 blocks away and the service was warmful and polite. The only problem was the shower. Like most of the Ibis hotels, the water escapes under the glass door to the carpet outside, and can flood the whole bathroom. Besides that, a good experience and very accessible.