To be honest, I used this, read Secrets, and first aid a couple times, and ended up getting 99th percentile. I think it is comparable. Especially if it is free from your school. People are way to caught up in qbanks imo.
You probably would have gotten 99th percentile no matter what you did. But that's not good advice for most med students.
For the rest of us, qbanks, namely Uworld are an excellent way to refine critical thinking and knowledge base. I'd say Exam Master doesn't come close to the level of difficulty on teh Step2 CK I just took, which honestly were harder than the average Uworld Question.
Uworld is the best. I was skeptical, then researched it and found it seemed to have the widest following, and excellent results. I think it did well for me. I felt very prepared during Step 2, albeit disoriented at times.