Hey Jim, Your update was very informative.
Sounds like you now have a beautifully renovated basement/HT room. I was concerned about mold growth as well. For those who use traditional foam or fiberglass batting with a vapour barrier, it does actually facilitate mold growth because of moisture entrapment.
For those who can't afford the Owens Corning system:
I opted for traditional materials (metal framing, drywall, etc) because cost was a huge factor for me. To alleviate any moisture problems, I have at least a 1.5" air gap along all perimeter walls, followed by metal framing (not wood) with insulation in-between, vapour barrier, and finally 1/2" drywall. I have two unfinished rooms (furnace and storage) that also allows moisture to escape (evaporate) from the air gap. Although not 100% full proof, I believe this does work.
For flooring, I have a floating floor system- a maple laminate that uses a click system for seamless and tight integration (no glue, no staples, no mess). Even if you install a subfloor, you have issues due to wood 2x4 sleepers that still can soak up moisture. Carpetting also acts as a wick to draw out moisture from the contcrete slab. The other option would be to buy that DriCore subfloor that uses dimpled polypropylene base with fiberboard on top but at $6 (CDN) per 2 sq feet tile, it gets very expensive.
These are the methods I used to reduce the possibility of mold growth. I have a basement that, probably, is as dry as you can get, but every little ounce of prevention helps.
One catch to all this: to find professional, conscientous tradepeople who do quality work. I was lucky as I found someone through referral. I even have round corner beading throughout, even at the ceiling where the soffits (covering air ducts) are.
I also installed all the wiring (A/V, coax and CAT5e) and boy, you can save a lot of money if you do this yourself. I just tested out my sound system the other day- sounds great (at least to my ears)- no ground loops, no issues what so ever; I am one happy audioholic!
-Yama