Pros

It functions as it says it will. Offers the necessary options. Hides in the system tray. Not ugly. When your rule goes into effect, it's not a marked sudden change -- it adjusts gradually, easy on the senses, not alarmingly.

Cons

It only offers specific time intervals rather than the user's choice of hour and minute (i.e. it is not an option to select 9:05am or 7:20pm or 4:13am, only X:00, X:15, X:30, and X:45). Additionally, it's just plain funny that after you successfully run a rule, it asks if you'd like to tweet about it. C'mon... Really? I lol'd.

Summary

You set a rule with four options: 1) the rule is either ON or OFF, 2) which days the rule applies (work days, weekends, or every day), 3) what time, and 4) the percent of your master volume (from any number between 0 and 100) you wish to go into effect. Seemingly you can set any quantity of rules you please, although probably not infinite. This program is exactly what I was seeking, to use in combination with a task scheduler to fall asleep and wake up to my music playlists. It would also be vastly useful for keeping control if you have children in bed (as advertised when you start up Volume Concierge) or for those annoying "quiet hours" in college dorms. Simply put: the program does what it says. It's very simple to use. I like it!