These springs work very well. They were easy to install on my 2011 4Runner springs. I wanted something that would help hold altitude when the kids and gear were in the back or when we were towing something. The only problem with this is that my 4Runner's back is very stiff, even at a minimum weight of 5 pounds! I don't really notice any rear suspension sag, so it feels like my new shocks aren't even working. I can't fault the airbags because they do their job and none leak. But I'll add some longer springs and probably remove the airbags so I have a little better upward motion for my wheels instead of my kids bouncing out of their seats.