Has anyone used the PrepU software for Brunner & Suddarth's Medical Surgical 12e? I just had my 2nd med surge exam and did not do well at all...prior to this exam I have made excellent grades. My prof's questions are really difficult...unlike any that I've had in the past semester, so I am looking for a better study guide than just the text book. If you have used PrepU, do you think it is worth the money? If you have used something else that really helps, please let me know.