I did the Ford branded roll up cover from the dealer.
Pluses: Ford Service installed it, bed is completely exposed and since the cover rolls up over the top of the bed rails, there is no loss of storage the way you get with a canister system. It looks great when closed and locks with the locking tailgate. When it is fully rolled up, you get a cool,Ford Logo visible.
Cons: since it doesn’t go into a canister, you have to manually clip it down with straps every time you change it. There is no good way to leave the box partially open, it is either all the way open or all the way closed. There is a large lever near the tailgate that helps orient the closing of the unit. This is likely to get bumped from time to time. It also interferes with the Amp bed extender, which was my next upgrade.