I am finishing the rest of my basement and for kicks I insulated the ceiling (no other decoupling, etc). The insulation was a waste of money or at least did not have as much of an impact as I had hoped. I still hear the trash compactor upstairs, cabinets closing, etc. Now in my theater with WhisperClips, Green Glue, caulk, insulation, double drywall and attention to detail (not shorting and making flanking paths)...priceless. Its a system and insulation has little to no impact by itself. Insulation is a key component of an engineered system, but by itself does not provide a lot of improvement.
If I remember, insulation only improves STC values by 3 or so, which for a theater, STC does not account for the lower frequencies and thus has even less impact. "Special" insulation on top of that is not attacking the weakest link, and I would ask for data showing that it provides improvement over standard insulation. I doubt it exists.
Sound quality will not be upgraded. You are talking about isolation. If it helps reduce the noise floor it helps, because you do not have to turn up the volume as much to hear dialog and then turn it down during an action scene. But again insulation will not reduce your noise floor enough to improve isolation. Sound quality will be improved with acoustical design of different materials and placement within the room, not in the construction of the room.
Start running if they are recommending spray foam insulation for the upgrade.
Edited by GRBoomer - 8/5/12 at 11:09am