Let me get this straight.
You have 5 days in Buenos Aires.
First night in Sheraton, last night in Sheraton and then 2 other hotels in between?
Unless you are there to write about hotels (a la Rick Steves or Samantha Brown) that is crazy talk.

Forget the hotel and enjoy the city. Stay in the same place.

Buenos Aires is amazing. Incredible street life, comparable only to Paris, amazing food, the people are wonderful, great architecture and the best Gelato west of Nice (France).
By the way, I really like La Borgougne. It is classical French food in the Alvear Palace Hotel. Arguably, named the best restaurant in South America. You should also hang out in the bar at Alvear. Very classy place.