Like as been mentioned There are ups and downs to both. I have not had a topper since the early 90's. My currant truck came with a ARE Fiberglass cover and I loved it until the dog got big enough he had to ride in the kennel, and that has to go in the back. Be fore this happened i use to pretty much pack all my camping gear in the truck in the spring and not take it out until after the last trip,(stoves float tubes ect). Make a list of how you are going to use it. With my cover it is not overly hard to move it just takes two to 3 people. I imagine the fiberglass covers will take a few guys to get one off as well.
Nice looking truck I love that color.