I like them as well. BUT, when I was under my 2014 a month ago removing a few items before I sold when I looked up into the rear dually fenders I could see the shadowing of rust starting to show on the inside of the fender and it perfectly matched the trim on the outside. That's the only issue with them, especially if you live in a salted winter roads area. As well on that truck one of the front fenders where i had the mud flaps screwed in, the 3/4"-1" wide steel lip that is there behind the plastic trim had literally rusted to flakes! I was stunned at how bad it was for only a five year old truck! All the more reason to not keep these trucks longer than 2-5 years with a warrantee.
They are not sealed, so therefore they provide a place for dust, dirt & salt to collect and hold the moisture in and against the paint and eat away.