The point of those quests is to have an enchantment on a head or pants piece. The enchantment may be small, but it's better than ANY stamina/agility/spirit/intellect/str enchantment in the entire game. Like I said, it can go on the head (which NO buffs at all can go on). +100 HP is a lot because it's that or nothing. It'd be different if it went on bracers which can already get +90 HP anyway.
-Lasereth