The best features OpenVPN Access Server offers is whitelisting members in my company who have joined recently. It is really easy to use, and it is really easy to set up OpenVPN Access Server as an internal app.
When whitelisting members, I just add the name of the user. I go into User Permissions, add the name of the person I'm going to whitelist, and send them the credentials. They are able to log in and authenticate using an authenticator app and are easily able to onboard on OpenVPN Access Server and access internal apps.
It is easy to whitelist new apps that I'm going to host or when I've created a new VPC. I will do the VPC peering where I have hosted OpenVPN Access Server, and I can easily add the IP or CIDR of that particular new VPC or subnet which I'm going to use for my new app in the UI.
Before using OpenVPN Access Server, only developers mainly had access to databases. We can create read-only users for databases and internally give them access using OpenVPN Access Server. It has been really useful, as we don't have to give access to everyone, and just give access to OpenVPN Access Server, and they are able to access databases or internal websites.
The change has mainly led to the onboarding process being more smoothed out. It is really fast and saves developers' time. It saves my time as a DevOps engineer, setting up things for people.