Comment 58 for bug 259214

Connect automatically means this connection to be applied as soon as possible after startup, without your assistance.
System settings means this connection is system-wide, not user's, so it is accessible and can be turned on by any user, or even before any user login.

I see people who do not understand this bug. (maybe I do not understand too, so correct me if I'm wrong) IMHO, name should be changed, because NM SAVES settings, but:
- It cannot save them system-wide because of this bug (so connection before login is impossible, automatic connection priority for custom setting is low, because default settings have system-wide status and used first)
- It can not change default connection, except "Connect automatically", because it is a feature. In ideal world without this bug, the only thing you need to do is to create new connection with your settings, make it system and automatic, and uncheck automatic for default connection, so default connection will not be used, but your custom will be. But in our buggy world you just need to click on your custom connection every time manually.