In SQL Server 2012 and 2014, creating an Availability Group could take a significant amount of work. One of the more tedious tasks is setting up your replica databases. This is because that you need to restore your database to your replica node in a state close enough to the primary to allow synchronization to happen. It can take several log backup restores to hit that magic window where you can join the database on the secondary node. Then, you get to do it again on the next replica!
Enter direct seeding in 2016. With this feature you no longer have to do any of the restores. You simply create your replicas with direct seeding enabled, then when you add a database to the AG, SQL Server will directly seed the database to your replica nodes. It’s surprisingly simple.
This sounds pretty interesting.