I'm positive I need them. I felt the rig move at every movement of my son in the overhead bunk (I was in the back bed). I also felt the rig move at every wind gust while parked. If felt like my son was jumping up and down in the RV.
Plus, traveling home, my hands were cramped and sore from having to grip the steering wheel so tight. It was a very windy drive home and I was having to fight the whole time trying to stay in my lane.
I don't mind paying for the Hellwig sway bars but I don't want to pay for installation if I don't have to. I don't have a vast assortment of tools. Just your normal tool kit you get from any home improvement store. Something similar to this -
Average tool kit from Home Depot