It depends on your fluency and confidence with which you present your insights to the discussion. The panel is a keen observer and if you try to act smart then your chance is gone.
Be precise and put on the factual data in your talks. There is no need to be over performing and rather stick to the basics. Start it well, put a strong point beside encouraging your peers to speak, and conclude with a solution.
For PI again all you need is confidence, knowledge and right attitude. Attitude is something more valued here. So if you carry that well and present a promising future then for sure you will get through. Needless to say that maintaining posture attributes are necessary as they come in complementary