I had a Ram 1500 with a rollup bed cover. It seems that whenever we camp it rains and every time I'd rollup the cover everything would get wet.
When I purchased my Ram 2500 the weight was over 6000 lbs so NYS DMV forced me to register the truck as a commercial truck. With commercial plates, I could not park in many parking lots, couldn't go to parks and could not drive on NY Parkways. Living on Long Island if you cannot go on parkways, it takes you forever to go any where. I put on a full cap, reclassified it as a station wagon and now I have passenger plates.
I love the full cap for camping. I put some shelving in the front of the bed where I can neatly store camping gear, cooler, grill, chairs etc. We camp just about every weekend from May to October, so for the entire season everything stays in the bed locked tight, secure and most importantly to me DRY.