Is it me or are the Stalla practice exams exceedingly hard....?

Im not scoring in passing range mostly 64-68% range with practice exams and passing everything in qbank. But for some reason, the Stalla Mocks are kicking my a$$. Scored a pair of 56%s on the mock a couple weeks ago and another pair of 60%s tonight. Anyone else finding Stalla harder than the rest?