Couple of times, in various places, I was asked: what is the benefit from upgrading to some_version.
So far, I just read release docs, and compiled list of what has changed.
But this is not necessarily simple – consider upgrade from 9.3.2 to 10.2. That's a lot of changes.
So, to be able to answer these questions faster in future, I created a site: Why upgrade PostgreSQL?.
Usage should be simple – pick from which version you want to upgrade, to which version you want to upgrade, and press gives me… button.
Hope you'll find it useful.