Maintaining a static volume level between sat channels and internet streaming has always been a problem for me. I've played with some plugins such as Automatic Volume Adjustment and some times it would work and other times not.

The current version of ATV has a Volume Adjust in the main menu which when set seems to do nothing no matter what adjustments are made. I uninstalled it completely, rebooted and now the same volume level is maintained between sat channels and streaming channels. No longer need to keep adjusting volume levels.

I hope they don't make any changes in the next build that may offset this.