No Ram boxes here. They would be useful but they prohibit you from using a rear cap, which I keep on my truck because I'm quite often carrying table saws, chainsaws, miter saws & stands, air compressors, etc to job sites and I need something big enough to hold all that plus materials and can be locked and keep power tools and such dry. If you have Ram boxes the best you can do is a tonneau cover.
If you only use the bed of your truck for hauling big or dirty opens or dimensional lumber, and don't need to lock anything up or keep it dry (that a tonneau wouldn't work), then I would get them as they hold a pretty good amount of stuff. My house inspector had them on his truck and I was always amazed how much stuff he could fit in there (well, he had to take half of it out every time to get stuff but still).