Is the Skeleton Key better than the quest rewards for returning it?
What are the rewards for returning it?
well you get one of three nightingale powers
i took the one that mades you invisible everytime you sneak (for 2min), very usefull
the skeleton key on the other hand, changes nothing, just saves a little bit money on lockpicks (i buyed about 50 once and not a single one every again afterwards)
one thing to know is, it's a daedric artefact and counts toward the achievment, so maybe do that first
there are 16 artefacts and you need 15 for the achievment