I think I'm beginning to understand the reasons for airbags. Thanks to y'all for the education!
My plan has always been to try without 1st, if nothing else because of the cost of the product but I also want to make sure the setup is correct and not mask it with the bags.
We had a 35' 5er (with same truck) that had a pin weight of ~1900#'s (empty) and we didn't have much of an issue so I'm hoping it'll be a non-issue with the new setup. One of my bigger concerns, and the reason I asked was that this TH (maybe all?) have the axles further back to carry the toy weight. This not only increases the tongue weight when empty but can (might ... maybe ...????) increase the "bouncing and/or porpoising", as Sunofabeach else called it above.
Thanks again for the tutelage.