I currently have a peragon cover on my truck.
It is a hard folding cover, but instead of flipping up, it folds down into the bed. It is also easy to remove and should fit in the back seat of the truck.
Positives are you get full bed access when you need it without have to remove the cover. Also was less money when I bought than the extang and bakflip. Also has a great locking system. You would have to cut the cover off or punch the lock out to break into the bed.
Downside is, it takes some time to install, and if anything slides forward in the bed when the cover is closed, you have to move the blockage for the cover to fold down.
On my next truck I am going to go extang or bak though.