While on our FL trip we got sick of the poor airflow to the bedrooms and the noise from the main venting of the AC. While we are alone its fine as we just open up all the doors, but with the grand kids one or both bedroom doors are closed as some point in time. Read about this in this forum last year and put it on my list of modification.
Took about an hour to install, but went in fairly easily adjusting for the gaps in the instructions (AC units are slightly made slightly different so there is some interpretation needed).
Seems to work, but will require a nice hot day to give it a good test.
LINK