Likewise here, With perhaps twenty years left, I think about things differently. A twenty year warranty is a lifetime for me now.
I hadn''t even thought about rodents. My PEX is all exposed so unlikely to be teething exercise for rodents. I did have a squirrel cut through a plastic .fuel line on a Chrysler product though. I matched the tooth marks to a dead squirrel for a perfect fit. I have had thousands of % in rodent damage though. The house is fairly tight now and I run a diligent trapping program for the few that manage to sneek in through cracked doors but the out buildings ar e a different story. I had dinner with some friends , one of whom is a contractor. He waas doing a renovation on a 100 year old house and they discovered runs of electrical wiring in the attic where the rodents had stripped the insulation off leaving bare wires separated only by the air gap. Something to be said for running BX or conduit!
I have my house plumbed almost entirely with CPVC and PVC. Some of it has been in for almost forty years with no problem. It replaced all the old galvanized pipe.
Our well went out last year. The steel pipe rusted out where it connected to the cast iron donut that directs the water to the horizontal line and the entire length of pipe and submersible pump dropped some forty feet down to the bottom. The well driller managed to catch the end of the pipe and run a special tap(kind of like an easy-out) in so he could pull the old pipe. That's been replaced with PVC pipe now.