The Lange Path cards were ABSOLUTELY CRITICAL for me. I studied those while I was at the gym, and I can honestly say I got 10-20 questions right on the real deal because of those cards. The drawback is that they're pretty dense at times. For example, there was more information on the various types of Vasculitis's on those cards than there was in BRS Path (thankfully, as I had 7 vasculitis questions on my exam).
If I had it to do over, I would study those things exclusively and blow off BRS Path.
Good luck,
HamOn