I think this restaurant is part of the chain that includes Cachoeira Tropical. I have eaten at Lagoa Tropical twice, most recently on a trip to Brazil in March 2015. On both occasions the food was tasty and freshly prepared. The selection is more limited at Lagoa Tropical compared to Cachoeira Tropical, but there were plenty of options. One problem is that the vegan items weren't indicated and one had to ask, but at least everything was vegetarian--no meat items at this restaurant. The price was very reasonable for an all-you-can-eat buffet. The location is near a metro station (Santa Cruz) and easy to find. Unlike some of the other vegan/vegetarian places in SP, this has no table service - it's buffet only. My friends who I ate with were not vegetarian and they really enjoyed the food, so that's a very positive sign.
Cons: vegan items not indicated