Supports a relatively large range of native extensions.
RDS PostgreSQL 10 Supports native partitioning and most of the major features and tunables.
Supports connections over SSL.
Supports multi A-Z and Point-in-time recovery.
RDS PostgreSQL Gotchas and Limitations
No superuser privileges. RDS provides a role rds_superuser that can do most of the needed operations but there are some limitations.
Some major features are delayed compared to open source PostgreSQL.
By default RDS is spec’d with general purpose SSD , if you need better performance you have to spec provisioned IOPS SSD.
You can't use RDS as a replica outside RDS without using logical replication.
There are settings that cannot be changed and most of the settings that can change can only be changed using database parameter groups.
It’s harder to troubleshoot performance problems since you have no access to the host.
Be sure to verify that all the extensions you need are available. If you are using an extension not listed there, you will need to come up with a work around, or deploy your own database in EC2.
Many Postgres utilities and maintenance items expect command line access, that can usually be satisfied by using an external ec2 server.