restful routes, deciding nesting/session

I am running edge and am torn on whether to use the nesting of 1.) /
users/1/books or 2.) /books (and assume current_user). Also, #1
allows for /books (without a current user) where #2 does not.

#1 avoids the current_user restriction (i could log in as an admin and
not have to switch to a user's session to edit things, etc), #2 looks
better

Does anyone have any suggestions or know of anything recent (written
on close to whats in edge now) that covers this?

Also, if anyone can elaborate on the best-practices of using a
controller in multiple roles as I hinted at above (/books - no
current_user, and /users/1/books) that would be great. I haven't found
a good example that shows how one action can behave differently
depending on the nesting.