I have had the Pace Edwards Switchblade cover on my F250 for over 5 years and am very happy with it. It's not the cheapest cover, but is is very secure (vinyl covered aluminum panels) and durable. And to open it, just push on it and it slides, and a strap to pull it shut. Plus it is not too difficult to remove the canister to clear out the bed. It sits about level with the top of the bed and clears my 5th wheel hitch well.
https://paceedwardsdirect.com/p/pace...tonneau-cover/