I have recently completed this quest, for finding the 10 pages of notes for jiub. You get the first volume of his book 'Saint Jiub's Opus' and a very good necklace called the 'Locket of Saint Jiub'. It is 9 armour, 0.5 weight, 2422 value. and the description of it is 'Carrying capacity increased by 50 points. Increases your stamina by 50 points'. Therefore it is good if you're like me and always try to carry too much stuff.