Always a nice concept to have enemies drop the gear they appear to be using. It can get a bit too much in practice, though, if every or even most enemies drop their stuff. I do think that bosses should drop gear appropriate to them. A caster boss should drop cloth armor, not plate stuff. Just need to make sure there's a fairly equal distribution of boss types. And various monsters can drop any type or loot (or better, guarding corpses or chests with any sort of loot). Or even better, drop unique crafting ingredients and special accessories.
