I'm leaning towards the Access Roll-Up cover, no snaps, has side locks to keep them somewhat honest with the locking tail-gate, has tubular bows so it's nice and tight, adjustable tension, velco along the entire length both sides which is so tight you'd have to have pencil arms to reach in. What I like is that I can roll it up in seconds so I can use the bed and it's in the middle of the price range at $450 or so installed. I really like the looks of both the hard cover or a nice cap, but both are twice the money and can't be easily removed to go get a quick load of mulch, stone or sand. Here is the link to the site, although I've not used it to see if it works
www.accesscover.com
Threaded Mode