They work great in the boxes, lol. I just picked them up on Thursday afternoon and won't have a chance to install them for probably a week or two. That and the truck has a list of things to do to it in that time frame as well so it just sits for now. As far as I was told the HD series and the 5100's ride roughly about the same. It's just you can play with the height on the 5100's if you lift or level the truck and they have the weather resistant finish. The price difference was very little between the 2 styles so I bought the ones that won't chip and rust so fast, lol.