Polish language school, Sopot. Opinions?

I'm considering a 2-months intensive summer course, preferably in the North. Found an offer from one private school in Sopot - Polish Language School. Anybody who's done it there? How is the quality of teaching?

You may check some reviews from here:
languageinternational.pl/school/sopot-school-of-polish-for-foreigners-63904
Keep in mind that the negative opinions may be deleted, so the whole picture can be not clear...