Late to the party, but will chime in. I'm less than a week in with my new Rebel and I already wish I did not get the Ramboxes. It is a cool idea on paper and do have functionality, but they make virtually every aftermarket bed accessory incompatible. Seems like nobody likes to build aftermarket parts for the Rambox variation. Also, not even Mopar can get it right. Accessories that are listed as compatible with Ramboxes in Mopar's website are not compatible. If you do get Ramboxes and order stuff from Mopar online, make sure you select delivery to the dealer. They can return stuff for you, particularly if you're ordering larger things (drop in liner, bed mat, etc.)
Overall, I like them and use them, but if I had to do it all over again I would probably go without them. The bowing that happens wiith the boxes is significant enough to notice, but I don't really mind it to be honest.