1 answered Oct 14 '15 at 14:31 Pillsy 12.8k11 gold badge3535 silver badges7979 bronze badges I've been really shocked at how much the features supporting Associations and Datasets have changed my coding style. Association itself is very convenient, and a lot of useful functions (like Keys and Values) introduced for Associations also work with lists of Rules, and the way Append and Join work with Associations is very convenient, if slightly confusing, since you effectively override old rules in a list of rules by Joining a new list of rules to its front, while you Join the new rules to the back of the Association. We also got the function GroupBy, which is something I was constantly faking with some combination of GatherBy and Map or Replace. Also, the behavior of Map, Select and the like, which operate on the values in the association while leaving the keys untouched is very frequently the right thing, and has allowed me to dispense with many uses of MapAt or Replace. I've barely used Dataset in and of itself, but many new convenient "operators" were added to make working with it easier. My favorites are the infix @* notation for Composition, and the many new curried forms of functions such as Map and Select. Indeed, I use constructions like Map[f] @* Select[gQ] all the time. Post Made Community Wiki by Pillsy occurred Oct 14 '15 at 14:31