I do not have any experience in WSOP.....yet. I am playing in the Colossus with team Cardschat this year. A few years ago, I wanted to play in the Super Seniors event (65+)... I thought I would be one of the youngest, so I might have a stamina advantage over most players in their 70s, 80s and 90s. I finally qualify, and they lower the age requirement to 60...I decide not to play it because there were too many new YOUNGSTERS added. Besides, going as part of the Cardschat team gives me the opportunity to meet some of the players I have played against in the CC freerolls and meet Debi. I know it will be much more fun with others to hang out with.
My advice about playing against 50s+ players is also to play tight until you have a good read on your table mates...if you spot a weakness, try to exploit it...playing too tight for the entire time will limit your chances to chip up...wait for a monster, and all you will collect is blinds and antes.