So, I spent entirely too much time this week reading reviews and watching youtube videos.
What I have concluded so far:
Tri-fold Covers: They are pretty much all the same from company to company. There may be minor quality differences between brands and models, but not enough to justify some costing double what others cost. The pro for me is you get complete bed access. They all claim to lock with the tailgate, but a crowbar could defeat any of them in under 30 seconds.
Retractable: Pros are full bed access and key lock. Cons are you lose bed space and cost.
Peragon: Pros are full bed access, key lock, and fast removal. Cost is also not terrible. Cons seem to be build quality and you cannot put tall items near the cab.
Diamondback: Probably the most durable and secure for under $2k. Cons: you do not have full bed access and is the most expensive of the group.
Did I miss anything important? I also always welcome alternative and dissenting opinions.