I haven't had any time (or space) to do any audio for 6 months because of the never-ending renovation, but last weekend we stuffed the ceiling and walls with insulation before starting the plastering.
SIGNIFICANT improvement in acoustics will all that fluffy polyester around. I'm thinking that the plaster will just muck it up again. ;-)
Mind you, since the reception I got from bringing home the 3m, 300mm dia tube for the Transmission Line sub, I think my no-plaster proposal is a "long shot" :-D