Borderlands Coop Play - Do both players benefit?

i bet your problem was that you were farther than him in the story. if he plays solo to were you are then you play coop then he will get the same rewards and xp as you. monsters will also become stronger but you get +25% more item/wep drops per player in the game and any items or weps you do will recieve will, on average be better. the best way to get the noncheat Uber weps is to have a game with 4 lvl50's with rare item or item scavenge class mods (sniper has scavenge and lilith has rare). then go to good chests. (yes! some chests have better loot than others!)

the 2 chests that i know for Sure are the one in new haven on top of scooters and the one in the dhal headlands in that cavern where you encounter guardians. you have to do a quest to get down here and you will have to kill a badass/badmutha/superbad guardian Before The Chest Will Apear. my bro got lots of orange and yello weps here when he was lvl 20! without any item mods!. i have not been able to get a good item team together yet.

if you want to help i will duplicate any good items we get for everyone if you really want the drop. my name is "skellyton5" and ill be on 6:30-8:30 est

If he already completed those quests on his game, then he won't get exp bonus for them.