Nothing but excellent
I wanted to prepare for the Certificate of Proficiency in English, so in July of 2020 I signed up for English classes with Naked English Mentoring. A year later, and thanks to the attention and dedication of the teachers there I was able to pass the exam. It required a lot of hard work for almost a year, however, I do believe that it is worth it, since this certification can be really helpful in my professional career.
I will recommend Naked English Mentoring strongly to anyone who wants to learn English or to get a certificate, since my experience with them has been nothing but excellent.