We booked a room at Five after reading reviews that mentioned its cool design and good location. Alas, because of the Aerolineas Argentinas strike we didn't get to stay there, but we did have to pay them anyway!
The airline strike left us stranded in Mendoza where we scrambled for a room for the night and contacted Five as soon as we saw that all of the flights were cancelled. We asked Five not to charge us because of the airline strike but they refused. We pleaded with them in several emails and then in person the next day when we finally arrived in B.A. They curtly pointed us to their 72 hour cancellation policy and wouldn't budge. While we understand that the problem wasn't theirs, it wasn't ours either.
In contrast, the Park Hyatt in Mendoza, where we ended up staying the night that we were stranded, stepped up and told us that when we arrived in B.A. we should go to the Hyatt to store our bags for the day and freshen up in the Spa before our flight to the US that evening. When we arrived at the Park Hyatt in BA the staff was aware of our plight and treated us like long lost relatives. The level of customer service was impressive - something that will stick with me for a long time. The lack of customer service at Five will stick with me too.
While the hotel is small, we found out that it was all sold out that evening, so they would have foregone only our $150 payment (which promptly appeared on my credit card). I fear that they will lose more than that in the long run when people realize that this hotel puts customer service at the bottom of its list of priorities.
If you can't afford the Park Hyatt (which is one of the most amazing hotels I have ever seen) and want to stay in Palermo, you're much better off at the trendy BoBo Hotel where the staff will bend over backwards for you. We stayed there earlier in our trip and loved it. BoBo and the Park Hyatt understand the value of good customer service in the hospitality industry - treat guests well and they will return and encourage others to do so, treat them poorly and they will spread the bad word. So, stay at the Park Hyatt or BoBo and steer well clear of Five, especially if you're flying on Aerolineas Argentina!!!