Stayed there 5 nights Jan 1 - Jan 6 with Mrs Meineke and just-turned-5 Tim Jr. I'll try to repeat what's been put in other posts:
- when I got my reservation reminder, it said it was a smoking room. I called the Diamond desk and told them I wanted non-smoking, they said there's was nothing avaiable. Also wanted early check-in (we landed at EZE at 6:30), they said they couldn't promise anything. Said I wanted a room with 2 beds, same response. I am pleased to say that when I got to the hote, they gave me the EXACT right answer - "Mr. Meineke, we see that you requested a non-smoking room with 2 beds. We don't have a room like that right now, but why don't you and your family go into the lounge and have some breakfast, and we'll come get you when the room is ready". Which they did 45 minutes later
- the food in the lounge was OK, not great. They kept running out of Diet Coke (I go to a lot of conferences and this happens a lot; when are hotels going to figure out that a lot of people only want to drink diet soda, so they should stock accordingly). Some days they did have diet sprite. Beware of the croissants - they are very heavy - I'd advise only eating the flaky outisde and not the dense inside. They are also very big on having you sign the ticket to say what room you're in
- my son loved the pool and the pool table in the lounge
- the lobby area seemed like a popular place to eat, so we tried it. the food was not very good
- not a fan of Puerto Madero area generally. Very sterile on the Hilton side, and theme-parkish on the other side. Plus a ton of mosquitos (who fortunately did not make it up to the pool), including in the adjacent park
- the 2 computers behind the desk on the 7th floor seemed booked a lot, and they closed at 10 (and 10 for BA is not all that late!). One night I went to the biz center to use a computer, there was no-one there to give me the code. Misunderstanding a previous post on this thread, I went behind the biz center desk, where there was a Lufthansa lounge with computers. Not clear if this is supposed to be open to the public so I used it just that once
- a lot of the landmarks in BA are under renovation. If you're trying to decide between going in 2010 or 2011, I'd wait a year
- many cab drivers didn't seem to know where the Hilton is. Three tips that seemed to have helped 1) pronounce it the HEEL-ton, 2) mention that it's in Puerto Madero (not a lot of name recognition on that one), 3) the street Macacha Guemes changes to Avenida Juan Peron once you get out of Puerto Madero.

All in all a very nice property, but perhaps more suited for a business trip than for a vacation exploration of a vibrant city like BA