Our Georgetown (used purchase) has toppers on both slides. We didn't realize that the living room slide topper had rotted out. The MH had been parked with the slides deployed and the living room side of the rig had been facing south for a couple of seasons.
With the topper having lost all its vinyl and just leaving the fabric threads in place , we got rain water in the dinette overhead cabinets. My take on slide toppers is that they offer additional protection against rainwater on the slide roof making it into the interior. We had a minor roll-over in the top seal that allowed water to get inside because the topper wasn't functional.
We're definitely fans of slide toppers.
Frank and Eileen
No longer RVers or FR owners