I know, trust me. My druid has 3 sockets and 23% leech, and he is basically unstoppable... and I haven't equipped his pants yet because I am hoping to find something better than the 840 with no tertiary I have in my bags. he also has tons of speed built in, which was just a bonus, I don't go looking for it, but if it is there I won't argue. Here is his page:
http://us.battle.net/wow/en/character/bonechewer/shadowhorns/simple
My hunter is about the same :
http://us.battle.net/wow/en/character/bonechewer/shadowshotz/simple
He is at 18% leech, but with my spirit beast healing me and all the little extras you get for being a hunter (like having an infinitely-battle rez-able tank in my pocket) he is also pretty much unstoppable. I have a replacement 835 six-feather fan with leech on it, but I haven't decided if I want to equip him with it or keep it for another toon...maybe make a Shammy or something, because even at his current 18% he is almost un-killable.