Hi Kenan,
I am sorry I would not be able to give you any specific recommendation on the PMI practice test, as I didn't have the opportunity to take it during my preparation.
However, based on what you mention about some similarities with the previous two exams, I think it wouldn't hurt. I understand it may be frustrating at times but I believe in the end it could be helpful for you to become more familiar with the way questions are formulated, if you find them closer to the real exam formulations in your past experience.
Meanwhile, if you have time, I would keep practicing the PrepCast exams to further improve your preparation.
Hope that helps,
Gabriella