Hello,
Our 2002 Jayco 324G was built with a TPO roof. I purchased the trailer seven years ago, I do not cover it. I have never had a problem with it. I do my regular maintenance every year which includes cleaning it with my Hotsey steam cleaner and applying self leveling sealer over the sealed joints when they start cracking. The roof is if excellent condition and in my estimation has many years of life left on it. I would strongly recommend TPO for a roof material. If and when I replace the roof I would definitely replace it with TPO.