Gaming Dilemma

I’m conflicted; I have been running 1st Edition GammaWorld at DunDraCon for years and years now.  I love playing GammaWorld and keep hoping to inspire others to also run the game.  I am probably the GammaWorld expert at this convention.  Every year at least one person claims they will run next year for sure so that I can enjoy myself as a player, but they never do.  I am tired of running GammaWorld each year and having to come up with a new adventure each time (I get repeat players).  Most years I have to turn players away - one year I turned away 20 people.  I am thinking about running a Cyberpunk 2020 game this year instead – I love the setting and really enjoy the few games I get to play at DunDraCon each year.  The problem I am having is in confidence; I am far from the expert in the game system and several of the regulars have been playing and running CP for years.  I am conflicted do I work in my comfort zone and play a game I’m growing tired of or do I take a chance on going down in flames as a convention GM with a new system?