I second reviewing tests to improve your skills, and while I don't think going through every test is necessary, I think going through as many tests as possible/won't burn you out can help you figure out to the greatest extent your strengths/weaknesses and address them pre-test.
For example, if you take 5 tests, you might see a trend that your weakness is justify questions, however, over 10 tests you might see a bigger weakness with parallel flaw. Something like that.
So, my advice would be learn as much background info you can before going into any PT, and then once you feel like you can't really get anything else out of prep material, start taking tests and reviewing them to figure out what prep skills you need to re-examine. You'll know when taking tests is doing you more harm then good (aka burnout, fatigue, IHatetheLSATsyndrome, etc.).