Just two dinners to report thus far...
Puerto Madero: Went here off the back of recs on the board. It's an Argentine steakhouse. The place was packed! Our table wasn't ready when we arrived for our reservation, so we sat outside on the dock on the water which was really nice. The best part of the evening, actually. I could have happily stayed out there all night.
Once inside, the service was manic. I felt like the servers were constantly running around. This is not a bad thing at all, but it was just something I noticed. They were all in a hurry. We started out with the chorizo, which was just a sausage. I wouldn't recommend this. Also had three types of empanada--meat, spicy meat, and ham and cheese--they were okay. And we had some fried cheese which was nice. The bread basket was pretty great--served with some tapenade and some salsa verde? And garlic butter.
For my main, I had the seared tuna on mashed potatoes and while the mashed potatoes were great--lumpy and garlicky and buttery, just like I like them--I thought the tuna was heavy handed. The slices could have been thinner. Portions were HUGE--our taxi driver later told us that everyone likes Puerto Madero precisely for that reason. Two members of our party got the surf and turf and they enjoyed it. This wasn't a gourmet experience by any means...it was solid, dependable meat and seafood. I don't think I'd seek this place out again.
We also ate at Hacienda El Mortero. They have a live mariachi band, which was fun. Complimentary chips and salsa, which appeared to be made on premises and were a nice touch. Served with pico de gallo and salsa verde. One member of our party had the tortilla soup and loved it. I had the shrimp served with broiled pineapple and rice and veggies. It was good, but nothing truly outstanding. In fact, the shirmps were served a little on the cold side, despite arriving accompanied by fire. (For the broiled pineapple.) Again, nothing truly gourmet. Large portions. Oh, and the margaritas are HUGE. Again, not a "must" destination for me.