They are all strong and safe.But only as safe as the user. This means that even in a lowly ladder stand mishaps can happen so you should be wearing a full body harness. Ipersonally knew one guy who fell asleep in one, fell out and killed himself. His wife and two young children are the real victims.
What to consider most is your comfort when in it. Portability sure isn't what they are about so you may as well have one that you can stayin and stay still.
Aas faras strong is concerned they are almost all alike. The same 1" tubular steel. The same 300lb weight limit, unless you get a double that normally carry a 500lb limit.