I've taken 8, and I plan to take 5 more before the test day. My prep course instructor, as well as my pre-law advisor, both agreed that it is not good to take tests daily. On the off days I am going through and reviewing a question type each day. EX: Monday-LR Flaw, Tuesday-Games Matching, Wednesday RC Main Point, Thurs Exam, etc.
The final week I will be taking an exam every other days and reviewing all question types on the off days.