Regarding the lippert pin box being a "Joke", no argument from me. Actually, the whole lippert frame isn't any better. Minimally designed to put it mildly. That said, I believe the 1621 and 1621 HD are the most widely used pin boxes out there right now on the rigs around 16k
Regarding the bed mounted hitch, obviously I agree hence the decision to go with the puck mount B&W. It's a much more solid hitch, and by the end of Oct I should have 3k or so miles towing with it so I can asses better.
Other issues with the Andersen, first trip to dealer with the trailer for warranty work, when I went to pick it up, couldn't lock the hitch adapter pin. Little ding in the lip of the adapter had to be sanded out to get the pin to slide easily. Didn't think much of it. Second trip to dealer, same thing, only worse and the dealer replaced hitch adapter for me. Suspected culprit is the ball setup they had on their forklift. They adapted a different setup for the Andersen for the future.
I also have occasionally had a loud POP, that happened if braking hard, accelerating hard, or most commonly when the 5er was pulled or backed up in soft soil/gravel where it sank in a bit. Finally got someone to drive the truck while I rode on the running boards to see what was going on. Seems the hitch base would slip just a hair under certain conditions, less than a quarter inch but it would jump all at once and be loud when it did it. Probably related to the spray in bed liner and a rubber mat or something would probably take care of that. For the record, the hitch adapter was torqued with weight on the ball. It's a pain to do as well, because with the hitch adapter set with the ball behind the pin, this means you have to jackknife the truck so you can crawl in there to get on the upper bolt with the torque wrench. Kind of a pain in the tush.
Anyway, I had high hopes for the Andersen initially, and talked the dealer into getting me one when I bought the trailer. I really like the concept. When I actually got it instead of reading about it I was a little concerned initially, but at the same time excited by the ease of installation and removal. Being someone that uses the truck for "truck duties" from time to time, and having several ruptured discs in my back light is good. Hopefully they'll come up with a better design in the future that works within the somewhat poorly designed trailer frames that rule the day.