i am a pretty above average player it seems. all those high ranking parses (the orange ones) i have are from doing some silly things. taking enough damage to be considered a tank but otherwise spending most of the fight not in tank stance, one was completely by accident (didn't swap to my dps spec in time). On thaddius i tank for a bit in my dps spec lol so i get an orange almost every week.
my shaman on the other hand i do VERY well on, but because i don't use potions or have professions that contribute to dps (she is mining/herbing) i am not quite the cream of the crop. but trust me when i say if i put the time in to grind i would be. enhancement shaman is fun and i feel like i have mastered it.