Okies,
Sometimes, druids ask me, why should I use/wear cloth armor? Why do so many high-level druids wear cloth caster or heal pieces?
The answer is, I hope, simple, and ONLY apply if you are balance, resto, or a hybrid of them.
Feral or mainly-feral hybrids should only wear leather

okay, here is why:
Items have points. They are called item points, and are based upon the level of the item (which is not the same as level to use it). The more points something has in one place, the less it can have in another.
So, something like D's Leather Gloves of Stamina and D's Silk Gloves of Stamina may having the same level to use, and the same item level.
But the silk gloves are cloth, which means less armor. So, they may have more stamina, because they have more item points to use there. Leather gloves are, well, leather, so they have more armor, and they are because fewer item points for the stamina bonus.
In Boomkin form, you get a big boost to armor anyway, but the idea is this: you are a CASTER, and should NOT be getting hit that often in melee. Soooooo, your points should be going into improving things like spell hit, spelldam, spell crit, Mp5, etc. - not armor. So start consider cloth for armor as ok!
And the same goes pretty much for healing.
If you are doing a lot of solo inside/underground, then losing the leather will make it harded as balance, and MUCH harder as resto.
There is getting more spellleather in game, and now +healing also get + 1/3 of the healing in spelldamage (+45 healing now = +45 healing AND +15 spelldam). So that helps.
Hope this explains it some -
~D~