I've eaten at ATS three times now and I've been consistently pleased with their food. The staff is friendly, there's a real buzz to the place (especially around lunch time) and the decor, while simple, is simply nice. While not a big meat eater, the carne asada tacos are hard to resist and the vegetarian quesadilla is terrific.
I'm sure there will be some who think the food is a bit pricey but it's all of high quality and, in my estimation, well worth the money. There are plenty of options for cheap Mexican. For my money, ATS is a great addition to the neighborhood.