Hi pdunc,
The float foam is a high performance high density polyfoam that has many of the properties of memory foam but without the slow response and very low resilience of memory foam. In other words it doesn’t leave a hand print when you push on the material.
The Float Foam is 4 lb density and with polyfoam I would generally look for a minimum density of 1.8 lbs/ft3 (2 lb/ft3 for higher weight ranges) while with memory foam I would generally look for a minimum density of 4 lbs/ft3 (5 lbs/ft3 for higher weight ranges).
There is more about high performance polyfoam in post #2 here.
Phoenix