They took a course at school last year to a child (14 years old) as a summer camp - I liked it, they did not regret my choice.
At school we chose to study German ahead of English, and therefore we were looking for the camp in Germany first and foremost. We were attracted the well-known name of the language school (this is a large network), the location in Berlin and the optimal duration, and on the dates of departure and arrival was convenient. My son liked the program: interesting, rich, not stressful in terms of lessons. It's nice that there are really a lot of foreign students (not advertising promotion), most Europeans - and practice (although they admitted that they also switched to English) and make friends with many children.
I note not so much as a minus, but as a feature: it is not exactly a city, capital camp. It is closer to the suburbs on the shore of the lake, to Potsdamer-Platz, in 10-20 minutes by public transport. On the one hand, it was beautiful and calm, such a cozy suburb of the middle class, on the other hand, he wanted more opportunities to walk around the city, see the sights and modern Berlin (although the tours were often organized, there were no complaints here). Apparently, specifically for us next time we will look for an option closer to the city center.