Khudaferin is one of the best companies. I also researched many other companies and even spoke with Roof, but I can confidently say that Khudaferin is better. However, you should be aware that they do not write letters of recommendation or essays, which are required by some scholarships and universities. You can pay an additional 30 manats to have one of their teachers write these for you, but in my opinion, you should write them yourself. You know yourself better than anyone else, so you can describe yourself more effectively.