I took 3 weeks of group classes at Vamos after moving back to Buenos Aires and wanting to get my already-passable Spanish to a better level. I took online and oral placement tests and was put in a C1 class taught by Agustina, who is a gem of a teacher. She brought in readings about Argentinian politics and social issues when I expressed interest in them, and she held us accountable while also creating a fun, supportive environment.
The social activities were great, everyday they would organize an activity either straight after classes - lunch and then visit to the Teatro Colon for example or a dinner in the evening. These were really great for getting to know the other students at the school and helped me a lot as a single traveler.
Overall, my impression of Vamos is really positive: I had a great teacher, enjoyed meeting the other students through social outings, and found the administrative staff helpful and competent.