Hi ResearchOverkill,
I would make sure that you know the exact foam layers that are used in each mattress and I would want more than just a “general” description of the foam density.
1.8 lb polyfoam would be a durable material in a two sided mattress (see the guidelines here) but I would also be aware that convoluted polyfoam isn’t as durable as a solid foam layer.
The 12.5 gauge knotted offset coil would be a stronger coil system than the Verticoil but neither coil system is likely to be the weakest link in either mattress (this would be in the foam layers) so once you know the specifics of the foam layers in each mattress if they are closely comparable I would choose the mattress that was the best match for you in terms of PPP…
Phoenix