Nothing outdated here. Actually after recent research in British and US history of R&D of composite armors, we currently know that Burlington armor was far more advanced in it's working mechanism and overall design than any Soviet composite armor design at that time. In fact Burlington cintrary to Combination K and similiar Soviet armors had dynamic nature, in fact it was a dynamic protection without explosive reactive material, however there was R&D work on it's variant with internal explsoive reactive materials, how they ended, nobody really knows because nobody without proper clearence do not know what variant of Burlington was fielded in the end, and there were far more variants of that armor that many people can imagine.
However in the second half of 1980's each NATO country being big tanks developer, US, UK, Germany and France departed from the original Burlington program and started to work on their own developments, but based on Burlington program experiences. And so US ended with Heavy Armor Package, that currently is in it's 3rd generation, UK ended with Dorchester armor, Germany with it's improved armor on later Leopard 2 tanks, and France with it's own variation.
There are of course other advantages of Burlington. It was discovered during R&D program, that effectiveness of protection depends on armor package volume, it means it's thickness, but thickness itself is not most important here, no, the real reson is that in bigger cavity, it is possible to place more layers of special armor, thus increasing time when projectile is affected by multiple layers of armor.
After comparing photos and drawings of Soviet armors and western solution, it was obvious that Burlington and it's "descendants" have advantage of many more layers standing in path of penetrator at the most predictible it angles. In case of T-72B it is max 5 layers, in T-80U/UD with so called "cermetal" pakcage, it is also around 4 to 5 layers. If we compare this to known photos and drawings of western type composite armors, we can see that there are actually space for many more layers.