I can hardly wait until you make the port and install insulation. The midwoofer sounds pretty good in a cabinet this size without a port, and response isn't peaky. But it definitely has less bass, having f3 of 70Hz. When you port it, you'll drop f3 by a full octave to 35Hz. And by adding the insulation, you'll improve midrange clarity quite a bit too.

Thanks again for keeping us posted with your progress. The photographs and descriptions are most interesting.