This barrio of Buenos Aires is very upscale. It is a very touristy and expensive area, because it is a part of an urban re-newel project that is taking place in Bs As. It is a cool Barrio to check out for about a hour in the afternoon, and then maybe come back one time during the night. In Puerto Madero you are able to take a couple of pictures and eat some food but that is about it.
Since Puerto Madero is a more "upscale" barrio, the food and drinks are priced higher than the rest of Bs As. There are really nice restaurants that are located along the Port. Most meals at these nicer restaurants start at about 30 pesos ($10 US Dollars), and then you will have to add drinks and a tip to the bill. I know that this doesn't sound like a lot of money before you start traveling, but when you are living off the peso you could probably live one day (housing, breakfast, lunch, and dinner) off the price of one meal at an expensive restaurant. There are a couple "tourist" restaurants like TGIFridays and Hooters for those that are craving some American food. Puerto Madero also offers ice cream shops, a movie theater (most movies are shown in English with Spanish subtitles), and a couple of bars.
As a part of the urban re-newel project, Buenos Aires made a path for people to walk up and down the port on both sides. There are a lot of tourists that sit down on the benches along the walkway and just hang out. There are also a lot of locals that just sit on these benches and make out. The PDA (public display of affection) is off the charts in Buenos Aires. It is cool to see the new buildings that are surrounding the port and all boats that are in the water. The port also has two boats that are in the water that you are allowed to walk on board and check out what an actual ship was like 100 years ago.
One of the best night spots in Buenos Aires, Opera Bay, was recently closed. It was located at the 
very end of the port (very close to Recoletta). This place was very big and was always crowded Wednesday-Saturday night. I am not sure what they are going to be doing with the property. I went there a couple of times, and never left before the sun came up! Even when the sun came up, they move the party from inside to the outside part which is located on the water of the Port. The party usually lasted until about 10am. It was always a ton of fun and packed with locals.
If you are traveling from Buenos Aires to Montevideo (Uruguay) then the easiest way to cross the river is to take a boat that leaves from the end of Puerto Madero. The company that runs the transportation back and forth to Uruguay is called Buquebus Ferry. The ferry runs multiple times per day and is about an hour trip. You can buy the tickets at the ticket window the same day or buy them a couple of days before your trip.
I was in Buenos Aires for almost 2 months. I went to Puerto Madero twice during the day and then walked around the Port one time at night. This is a barrio that does not offer too much to backpackers that are traveling on a budget. The nightlife here is almost non existent now that Opera Bay no longer exists. I still had a pretty good time the 3 times that I went there. It is definitely worth checking out during your trip to Buenos Aires, but this is not a major hang out for backpackers.
