Thanks, I figure it out. What was weird is when I unchecked the ObiTalk Settings box it automatically checked the Default box - I thought it was a toggle and tried to change the numbers. Then I realized I could uncheck both boxes and then it allowed me to change the settings. Very strange UI.
I've been playing with them and leaving myself voicemails on my cell. So far, I can't hear a difference at + or - 6