1. I found out that since two of my walls are "foundation" walls and there is a gap between the framing and the concrete foundation wall; they are in essence "decoupled" and would not require a whisper clip/hat channel application.
2. However, the idea of equal impedence and having all the walls/ceiling the "same" in regards to an approach, means it probably should be done the same all the way through and I am not sure about doing some walls a certain way and the others/ceiling another. Not that it is not possible, but perhaps a little more complicated.
3. The idea of the wall having flex to it and issues with hanging items on it - something my wife would really worry about and certainly having someone stand against it (or kids run into it) and having the wall "move" is something I may not want to get used to.
4. I am attempting to have a fiber optic star field in the center of the room and I am not sure how clips/channel would be done in this regard and avoid lossing too much of my height. I have a 9' ceiling, but enjoying having that height and don't want to lose too much of it either.
In the end; as interested as I was in decoupling - I don't know if clips/channel and certainly, a second wall, will be cost effective and somewhat "user friendly". The concerns regarding electrical outlets, recessed lights, etc. with the clips/channels may drive the cost of my electrician up and prove problematic at home (wife). I am also attempting to do some of it myself and not sure how to handle issues of sheetrock/tape/texture with the decoupled (clip/channel) wall.
If I was to do a double sheetrock wall (5/8") with green glue in between and R19 in the walls/ceiling all the way around the room universally -
do you the room will do a "suitable" job of soundproofing and do you "think" I will be satisified. Is there a point of "diminishing" returns with soundproofing in that the "noticable" difference to an average user with the advanced methods may not warrent the additional costs and efforts?