Borderlands DLC completion time?

hey guys..quick question. roughly, how long will it take me to complete the dlc for this game? i completed the story when the game first came out, but now im looking into the goty for all the extra stuff. thanks for the help

The zombie island of doctor ned should take around 9-10 hours but mad moxxi's underdome riot depends on how good you are at killing lots and lots of enemys without dying each round

seriously, 10 hours for zombie island what planet are u guys on? i would say more like.....

Zombie Island: 3-5 hours

Mad Moxxi: 14-16 hours (gets really boring and tedious in the large challenges though....)

General Knoxx: 10-12 hours

Claptrap: havnt played this yet, waiting on the patch that increases the level cap first, but from what iv heard its about 6-8 hours

you really can't value the dlc on single completion time, because most people will have several characters and even every now and then I go back and play them just to screw around. Not to mention this game is a lot like an mmo, the true game starts after you beat the game and hit the level cap