Hi whitesox20,
The edge reinforcement on the Caliber Edge spring units is from rows of springs using thicker gauge steel around the perimeter. This type of edge system provides a good elimination of product roll-off (the main function of an edge reinforcement system) and allows you to sleep close to the edge of the mattress. This type of system doesn’t tend to feel as “stiff” as some of the innerspring units, such as an LFK, using a border rod and high IFD polyfoam encasement, when being sat upon.
Memory foam is the best at motion isolation but latex and pocket coils are good for this as well (see post #18 here). Having said that … all the layers and components in a mattress will have some effect on the feel and performance of all the other layers and the mattress “as a whole” so the best way to test for motion isolation is your own careful testing on a mattress using the testing guidelines in the tutorial post (with both of you on the mattress) because a mattress that may be “motion isolating enough” for one couple may not be as suitable for another couple that is more sensitive. A foundation under your mattress would certainly contribute to having better motion isolation but it would depend on the type and force of the movement and on the thickness of your mattress as well (a thicker mattress would isolate you more from the springs). Traditional metal bed frames are also culprits in allowing people to feel more motion when moving atop a mattress.
Overall I would think it’s reasonable to say and most manufacturers would agree that latex is “good” with motion separation, especially the slower heavier types of movement such as turning over or bouncing or getting out of bed and are an improvement over other materials (except memory foam) but again this depends on the type of movement or vibration and the specific construction of the mattress, the ticking and quilting materials, and the materials or components above and below the latex and even the bedding above the latex as well.
Phoenix