Also depends on what class you are. If yer a mage/warlock, taking off your armor and not casting yer shield spell won't make that much of a difference. I think Soke (35 mage) has around...500 armor with the buff up? Half that without, which translates into roughly "soaking" about 15 percent of the damage. Whee. A mage's main defense is not to let the mobs get close to them, or kill them quickly. A warlock's main defense is their pet.
Warrior on the other hand, big difference. I'd imagine somewhere in the middle for the leather users, the rogues and shamans and hunters.
As for loot dropping, I don't particularly care. I remember DAOC fondly because of the random drops and the excited "OMG what was THAT?" moment I'd get when seeing it. A pair of +1 con green shoes was cause for joy in those days. I mostly play (and this is weird, I know) to satisfy my need for "phat lewt" in a game. I love CoH, but it doesn't have loot. So, if a wolf drops a pair of magic boots it's cause for joy in me. But then, I'm a big weirdo. Otherwise, WoW is just...ok for me. Nothing good, nothing bad, just kinda meh. I just needed my phat lewt, dammit! Well, that and hanging out with the pervy troll Rhoach is cool too. Oh, yeah, and Uld. And just about everyone else. I'm an awful soloing hermit in CoH so grouping is good here.