Yeah ADT's, and specifically their application to prevent NPE's is one of those things you never want to go back from once you've used a language which has that feature.
It seems like one of those fundamental advancements in language design, like when computer science collectively decided goto should be deprecated in favor of flow-of-control expressions.
It seems like one of those fundamental advancements in language design, like when computer science collectively decided goto should be deprecated in favor of flow-of-control expressions.