Always-On Read Only Routing vs External Load Balancer
Is it better to use always on feature "read only routing" or to use an external load balancer to balance connection between replicas ?


That's going to 100% depend on your needs. For example, if you're just wanted to have readable workloads hit a secondary, then inside of SQL Server should be fine. Now, if you wanted to hit the secondary that is closest (geographically) to your internal users depending on where they are... then you'll need some fancy rules and external load balancing.

Regardless which you choose, unless creating your own health check or probe the external load balancer will not know which secondary servers are healthy or unhealthy.


  does not need a dba to do network work


Neither of the ways requires a DBA to do "network" work, you setup the URL (SQL) and the list (SQL) and magic starts to happen.


  Does somebody have any insight or feedback on always on ROR?


Use it where you need it, it's just another tool in the collection. You may find that connecting directly to the secondary is better for your use cases and scenarios that using ROR... or you may write your own health checks for the external load balancer (if it supports it) to only route to secondary servers that take into account locality of the user.