OpenVPN configuration

[hw1380]

My router is a RT-AC68U with 380.58 and I have configured one OpenVPN connection to my VPN provider.
But I'm a little bit confused about the "Redirect internet connection" option.
I used to set this option to "All traffic" and I already used the "No" option for testing but noticed no difference in regard of the visible IP address.
I'm a little surprised that some VPN providers recommend the option "No " and some others the option "All traffic".
What is the difference between both options and which one is recommended ?

 

[RMerlin]

Some providers automatically pushes routes to the client. Setting this option to All Traffic would mostly override theirs, and force everything through it.