The warranty does vary, don't remember the details.
I got the "Elite" for that reason, I think it's two years.
(the Elite is stainless, I would've preferred black powder-coat myself)
Thought it was interesting though.... that pdf I linked above says the preferred mounting position for one of those gas springs is with the rod down..
I'm gonna check if the Redline props and my Snugtop props can be reversed to that orientation.
I know the Suspa brand, they make those props for lots of industrial and marine equipment, been around for a long time. If they rod-down is best, I believe them.