so i watched a video (i had the idea earlier but this video made me certain) about a mob item collector. i would build this room and the items would be distributed to the towns.. dont ask me why, i just wanna build something big and something useful. the only problem could be finding some1 to pick up all those objects

I've built that exact trap a couple of times. Works great! The last step of clearing the torches and sealing the room sure gets the adrenaline going It probably takes a good 4 hours to build each trap.

I've found that mobs only spawn when you're relatively close to the trap. It also depends on how many players are online, how many mobs spawn in there.