i think i have about 10 different hooks that i only use for fringe and for dropped stitches. i can fix both without but it is so much easier with. i don't know that i have a preference for materials but i do use the metal more...really just because they happen to be the sizes i am needing at the moment.
Hobby Lobby does have the coupon online this week. you can get a set of the Boye's hooks like the interchangeable knitting needle package that is fairly inexpensive, especially with the coupon.