Wrapped metal plenums > your ductboard plenums. Makes for a cleaner system. I'm rolling with the metal in my rinky dink house.
"My plenums are better than yours!!!!11!1
Apparently you don't even know what you're talking about, you have a supply and return plenum and those are attached to actual machine, and yes mine are metal.
Also both systems have trade clean effects filtration systems behind ceiling filter in a hose of mostly stone leather and other low dust making surfaces and sealed with foam insulation. So now that cleared up you lack basic terminology, why ask me about my zone system, like you're interested, jet to make some attempted insult that isn't even accurate!? And every vent has great airflow, they were all measured with air flow meters and I keep my house like a refrigerator yet my highest monthly bill is still less than $150 in middle of summer.