An aside, folks who have a tag says it rides better and steers better than a single.
But have those folks driven the same coach with and without a tag? Otherwise, how can you know what a tag does to help?
I've owned both, but my tag coach was a 36 footer with leaf springs. I replaced it with another 36 footer without a tag and it rode about the same overall. But the newer one was a longer wheel base and had a tighter turning radius (wheel cut), so it actually steered better. Now I drive a 40 foot non-tag with air suspension and a 57 degree wheel cut and that rides better and steers better than either of the other two. Do you really think that it would ride & steer better if I jacked it up and added a tag axle? I don't...
I'm not saying that a tag cannot help ride in some circumstances, but mostly what "people say" about ride and handling comes from longer wheel bases and heavier coaches, both of which go hand in hand with tag axles. And those are more expensive coaches too, so there are probably other enhancements as well.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL