My in-laws just sold their place. It took 2 weeks and they had 2 offers to work with; ended up getting full asking price.
I agree that neutral colors and de-cluttering are necesary. When I last sold a house, I was told to take the system out of the room and re-purpose the room to look like living space. I was hesitant, but eventually caved. Whether or not is helped sell the house, I don't know, but most people don't understand tons of records and big speakers, much less tube monoblocks and such cluttering up a room. It may be worth the sacrifice.
