Well.....The new return drop has been installed.....along with a horrizontal media cabinet.
First, the installation. I was with my duct pro the entire time and he used me as a pair of extra hands. Recall that he is in commercial HVAC now and is doing this as a side job since we both work at the same company (although he is still charging me $$).
The first thing he noticed when he took the old return drop off were additional flaws from the original installation. The bottom of the return EL boot was not sealed and the contraption that was suppose to hold the factory filter in place was mis-aligned allowing unfilted air to go around. Before installing the new El-boot he put a hefty bead of silicone in place acknowledging it is very difficult to seal after installing.
I have attached pictures of the before with the 24 x 10 return compared to the after with the 24x20 return. (Before anyone asks I moved the yellow Energy star Label from the side to the front of the unit (so you will only see it in the "after" pictures).