My old chevy had snaps. I dreaded having to open & close it during the winter and the three support poles were awkward to use.

My 05 Screw has a Lund tri-fold ($340). The cover and frame is one piece and the unit folds into thirds. Drop the gate, unlock a quick clamp on each side, fold the unit twice, clip each side to retain it, and you now have access to 2/3 of your bed. Unlock two more clamps and remove if you want full access. There are no rails to mount.
Can't be stolen without destroying it if the gate is locked. I've had it 1 year and no problems.