We booked a senior suite for a 6-night stay over the New Year holiday based on a recommendation and the great photos on their site. Only problem was that our senior suite did not have a small balcony as shown on the website or the neat looking indoor/outdoor bathroom. Instead we had a dark room with only 1 window to an interior atrium. As others have noted that means NO privacy if you dare to open your window. Which you definitely need to do because the air conditioning is out of your control (no in room thermostat as others have noted.) Felt totally ripped off. Would not have stayed if we hadn't prepaid.
Look, if you have one of those great upper suites on the top floor (which we THOUGHT we had) you will no doubt find the Vain charming. Otherwise you are in for a lot of noise. The hotel is indeed visually alluring...as you can tell from the website a lot of thought has been put into the design. But it is all Form over Function. The vast majority of rooms are accessed from the main interior courtyard and as mentioned that is also where you have your only window. Yet all the floors are concrete. So you can't help but hear everyone coming and going.
Inside the rooms the form over function principle remains intact....not one hook to hang a wet towel. No counterspace to place toiletries...seems that would ruin the aesthetic of the very hip sink. The first room we were shown (208) has a built-in along the wall that faces the bed--with two open (no door) closets for clothes. So once you unpack you have the lovely experience of staring at your clothes from the bed...Again, what looks great when it is not lived in, becomes icky once you actually try to live in it. We were moved to a quieter and brighter room...but even then we couldn't open the windows and pull the shades unless we were willing to put on a show for everyone using a stairway next to our window.
On the positive side: wonderful staff. Really helpful and lovely. And I saw some earlier comments about housekeeping not being up to par. We found it just the opposite...they were terrific. And the public living room on the top floor is very very nice.
If you book--and are actually given-one of the senior suites on the top floor you will no doubt have a great visit. Otherwise, I would consider looking elsewhere, unless you don't mind a bit of noise ands no air flow given that you will be stuck in a room with only access to a glorified air shaft/atrium. For the money I bet you can do better.

The hotel was very clean and modern. The staff were very friendly, spoke perfect English and were very efficient. Our room, in the 'I' range, was small with a very dark bathroom, containing a shower, toilet and bidet. The wash-basin was actually in the bedroom itself. The only window was the glass door of the room which led into the corridor so we had to keep the blinds closed.

Breakfast was excellent with very healthy options for Argentina.

The location was fantastic. Very close to the subway and on a lovely residential street, within easy walking distance of great shops and restaurants. We loved Palermo.

My thoughts on leaving the hotel was that it was over-priced for what you got and I'm sure there are better-priced options in Palermo.

Hotel vain is a nice and trendy hotel. The location is excellent in the SOHO style Palermo neighbourhood. Staff is friendly and helpfull and the rooms are stylish decorated. The only negative thing I can think of is the airconditioning system which is centrally controlled and is a bit noisy. emiel and karin from amsterdam

We had the pleasure of staying at the Vain Boutique Hotel for 2 nights in December 2007. This hotel was an absolute gem! We stayed in one of the V Suites on the top floor, and couldn't have asked for a better experience. The room was clean, beautiful, and relaxing, with several wonderful touches like free welcome drinks, complimentary spa mini facials, and surprises like chocolates in the room daily. The a la carte items in the room are also great and relatively inexpensive (ie: wine, champagne). The staff is very accomodating and helpful, and the free internet service is a plus. The breakfast was varied, fresh, and wonderful, as are the frozen peach bellinis if you happen to stop by the bar at night! Although this hotel is a few blocks away from the main Palermo boutiques and attractions like the zoo, botanical, and japanese garden, the location is convenient enough, with several wonderful dining and shopping options all within a 15 minute walk. I would heartily recommend this hotel to anyone and look forward to spending more nights there soon!