Anyone with opinions on paint protective finishes for cars?

My wife just got a new vehicle and is wanting to protect the paint job. I've been reading a lot about xpel. We are considering just doing the front end and mirrors, mainly to protect from rock damage and such. She is wondering if there would be any noticeable difference in appearance from a protected surface to an unprotected surface.

Do any of you have experience with this? Any opinions regarding xpel vs other films vs polymer coatings or anything else?

Thanks