I have already contacted that school and they seem OK.
My problem is that most schools (including Prolog) seem quite vague on their number of students, the number of hours and the exact location of the courses....
I don't know who exactly they take.. but I did see people that didn't seem to be students anymore. Anyhow, I took some classes there and would highly recommend it :) If that helps at all.
I would also recommend Prolog, excellent but pay them directly at the school on 37 Bronowicka and avoid the other school further away on the same street .
I can recommend Glossa School in Krakow. I participated in their course last summer, they have a very good Polish book (Polski Krok Po Kroku), experienced teachers and a very rich social plan (including pub evenings with teachers, many trips, Cracow walks etc). Here is their website: glossa.pl
You can also check their Facebook page (Glossa - School of Foreign Languages).