For me it's 4 things.
1) Competition - I practice hard then go to contest primarily to compete against myself. My goal is to always improve my raw score percentage regardless of how others do.
2) Different environment - As mentioned above I spend allot of time at my own field practicing. I love being able to fly at a different field every now and then.
3) Experience - Regardless of how the competition went (maybe the weather was not that great or maybe I didn't fly up to my expectations), the experience is very valuable to me and only strengthens my confidence when I return home. Last year I was at a contest the skys were threatening rain. Everybody before me flew under dark grey skies. When it was my turn to fly it started pooring rain. I looked over to the CD and he said "It's your choice" I took that to mean either I flew or I zeroed the round. Since I'm competeing against myself it was gut check time! I girded my loins, stepped up to the plate, turned aroun and told the judges "Lets Do It!" After the flight I felt great because I endured adversity and flew anyway.
4)The D6 culture - I just love the D6 culture. I'm very fortunate to be in this part of the country and fly with these guys.

Glen