Lilly,
It is going to be different in all cases. I was active on the panel for 2009, 2010, then off for 2011, then back on for 2012 and 2013. I am off now, and will not be back on in 2014. But even if I never go "active" again, I am still officially on the panel. I cannot stress enough how it has changed my life. I have made lifelong friends, the training trip was one of the most fun weekends of my life, and the fun of answering question on the DMP site is pretty amazing.
But we should all remember that we are our own little panel all on our own. As I sat on the floor at my 8-year old's volleyball practice, with all four park maps spread out, circling the "To-Do" and "To-Don't" attractions for another parent of a child on her team, I realized we are panelists in our own way. And helping out our friends and family is the most impactful panel experience there is!
Doug