Bimbert84
back in 2001 when i bought the "snap" cover i thought it lookes cool on the truck kinda sporty and "cheaper" than the othe types.
I have a slide in truck camper that sits in the pickup box, i use from time to time. The "clearance" between the part of the camper thay sticks out over the box rails is pretty tight. The snap type cover seams to have the lowest height of the "rail" that run the lenght of the box. Threfore I can leave the rail on the box while using the camper.
Also you can acess the boxs front coners by just unsnaping a few snaps in both directions fron the corner. which is a feature i use when pulling my travel trailer.
All covers have their good and bad points. just a matter of what suits "you" paticular needs.
Happy Camping!!