There are a few guys on this site that have strong opinions about goose neck adapters like the Andersen. I have NEVER heard or seen testimony that the Andersen adapters will damage the frame of a 5th wheel. I think with only a couple of inches of offset, there is not enough added leverage applied to the pin box to actually tear or bend a frame. They have been building and selling these for a long time and I would think they would be off the market by now if they were damaging trailer frames.
This my first 5th wheel and with the rear living space and center bunk room, it's the perfect set up for my family. I will admit, backing up a 5er is a little trickier than a trailer. Its going to take some practice for sure. Also it's definitely higher than my TT and we won't fit into some of our old favorite camping spots.