+3 on the Diamondback. Had several hard fiberglass covers before and the Diamondback with front and rear closing panels is much more "user-friendly".
As a bonus, when hauling larger items the support shocks quick connect and make it easy to fold the panels forward or backward to allow for easy transport. I recently made cabinets for my son's garage and transporting them both on top and inside the bed with the lid open was a lifesaver. Went with the 400# version as I don't plan on transporting anything that heavy on the lid. As far as inside storage, the "bump" in the lids has actually increased the storage over my hard fiberglass tops. Highly recommend.
Think like a Proton-Stay Positive!