I have pop up truck camper and love it. The hard shell truck campers are nice but I wouldn't have one for various reasons. Check out the Rv for sale websites for a good used one if you already have a large enough truck.
Love my camper
I have had a Outfitters 10 years and I love it. Mine is only 6.5 ft long and is plenty big for 2 people. I have spend as many as 28 days in it. Soft sides do have there downsides but all in all its not a big deal. They do shake a little in really high winds and if not seam sealed...