My F250 has a plastic liner that was installed new by the dealership. It has been great. Two reasons I wanted it over spray in.... 1. cost, plastic liner was included in deal, would have had to pay extra for spray. 2. The thick, ribbed plastic liner helps to protect the bed from getting dented.
My plastic liner was custom fit to the truck, so I've not had any issues with it moving or anything like that.
Hauling landscaping timbers, materials, tools, etc the bed has been great.
If I wasn't using my truck as I do, I would rather have a spray in liner. They look cleaner and neater.