On Monday we finally we to Tigre. We caught the train from Retiro station and wandered down to the water's edge and booked a trip to El Gato Blanco, which is a restaurant on the delta. It had been mentioned by quite a few people. We then boarded a boat and took the 45 min trip to the restaurant. It was a very pleasant trip and quite interesting to see all the houses and hostels on the little islands.
The restaurant itself was only okay, nothing special and quite pricey, but hardly surprising really. Then we headed home. It was a good day out.