I really liked the erpprep.com website and their team of exerts. I took the SAP Ariba Procurement exam and passed. I felt that I was confident and fully prepared going into the exam after my comprehensive practice here. Usually I am very nervous when taking exams but that wasn't the case here, I had clear concept on each subjects which was full of knowledge and was able to easily convey it to the class for all to comprehend although everyone learns at a different pace/level.
thanks, team erpprep!!