Buckling column gel is a newer material used in comfort layers which has some unique properties. It is not commonly seen although some recent changes in ownership and licensing have made it more available and it may become more widely available yet over time.
It is made of either hexagonal or square "columns" which will support a certain amount of weight and when they reach their threshold they then "collapse" under pressure. Because of this ability to be both firm in certain areas (to the degree of their threshold) and soft in certain areas (when they buckle), they have a good ability to form a cradle and offer a very good combination of pressure relief and lumbar support. They may even offer greater degrees of pressure relief than either latex or memory foam and are used in hospital applications for this purpose.
They are also a very durable material and while they have not been on the market long enough to know this for sure, a reasonable expectation is that they will last as long or longer than most other materials on the market.
There are some "down sides" to this material however. One of these is that they come with different "collapse" thresholds and the firmer ones (usually the hexagonal shaped versions) may be too firm for some people. They also have a somewhat different "crackling" feel to them which some people find is a little difficult to get used to and some have described as a "bubble foam" type of feeling. The second is that they are very expensive and like memory foam, require high quality support layers beneath them as they are not designed to be used as part of the deeper support system.
If you have rather extreme pressure relief needs, a buckling column gel comfort layer may be well worth investigating.