I've been looking for a replacement for RPG Soundmixer for some time now (since that program is not supported in Windows 7), and I hate to jinx it- but this seems like it might be the one I've been looking for!
The one aspect I was hoping someone would improve on is with the use of hotkeys. RPG Soundmixer allowed you to turn on and off the ability to use hotkeys, however, from what I recall you could only assign one key hotkeys. So, if you were doing any typing (entering in initiative states, tracking hit points, etc.) you would have to remember to turn off hotkeys, and then remember to turn them back on afterwards. I was hoping that someone had improved on this by simply allowing you to enter in two key combination hotkeys (alt+1, ctrl+h, etc.) I see that RPG Atmosphere allows hotkeys, but the implementation is the same as RPG Soundmixer.
Anyway, I am going to be using this in an upcoming session, so I will definitely provide feedback after actually using it in play.