New owner here, just purchased my 18 Sierra last week. It did take a week for me to take delivery on the truck, as it had the open recall for the rear defroster and the dealership replaced the whole back window (i do have the power sliding window as well). They had to order the glass, took about 5 days to arrive to the dealership and then the install took them about 2 hours. I have not seen any issues since the install granted I've only had it for a few days now though. Just thought I'd share my experience with this issue.