Like everyone else I gotta put my two cents in.
UV & SL filters are just cheap insurance for me. Whatever dust & smudges I end up cleaning off at the end of the day is removed from the filter, not the lens. Each lens has it's own resident filter & that's the way it is uh-huh!
If you've been in the retail end of the camera biz for a while you will have met customers who come in with broken or bent filters to be removed & replaced. If not for the filter it would have been the filter ring or possibly front element of the lens. Filter rings can be straightened glass can't.