A recent Twitter poll asked What is your favorite upcoming feature of PostgreSQL V10? In this admittedly unscientific survey, "better parallelism" (37%) beat out "logical replication" (32%) and "native partitioning" (31%). I think it's fruitless to argue about which of those features is actually most important; the real point is that all of those are amazing features, and PostgreSQL 10 is on track to be an amazing release. There are a number of already-committed or likely-to-be-committed features which in any other release would qualify as headline features, but in this release they'll have to fight it out with the ones mentioned above.
