I have used the Excelsior practice exams and gone over the SG101 practice exams. The Excelsior exams are more like what will actually be on the exam, in my experience. The SG101 practice exams seem more like an overall, broad subject review. They ask questions differently than Excelsior does. Focusing on the Excelsior exams and the SG101 study guide content (the reading part) has served me well.