Good overview. I've had a few MX4's they are probably the best tri-fold out there. I hated hauling anything large in the bed though as you end up with the cover against the window which blocks you view (but also does protect the window), but it will also kill your gas mileage if you are doing any sort of distance. Although with the rambox version being narrower, maybe not an issue. My brother had one that the cover collasped on him (RAMbox version) not sure what was up with that, but Bak did replace it.
I personally switched to a Retrax Pro. You lose a bit of bed space, not something you'd want with a RAMbox truck probably since you already have a small bed, but the ability for the cover to be locked in any position, allowing to pinch cargo, and not blocking the rearview are benefits. I also run the Retrax Pro XR version, so i can run a roof rack on top of the bed, to haul my MTB's.
Great job though!