Ahh, I use GearScore all the time.
But I have never used it to exclude someone. As lead Healer I use it to identify people who might need extra heals or help healing. It's a tool like anthing else and if you dont understand it it will make you look like a noob.
[rant]
OMFG Hit Cap, it's like people just dont understand mathematics or something. Sure, dont replace 50 SP and 20 crit for 2-4 Hit, but you should be aiming for max +Hit. I have had this discussion with Mages, Shaman and Huntards. Same people probably believe the
gambler's fallacy is true as well.
[/rant]
The single most important part of playing is knowing what the f**k to do.
Stand out of the Void Zone.
Go to the tank to remove Paralytic Poison.
Take the Burning Bile to the Tank.
Stay in range of the healers.
[rant]
Stand the f**k out of the f**king fire! 50minusDKP 
[/rant]