Really woke up the engine...
The filter kit arrived the day of completing a 200 hour service including valve lash. Installed kit right away.
Test cut was a 90 by 300 foot sq. area of 5-7 inch Bermuda, blue stem hay grass (way higher) and pasture woody plants.
Mowing at normal speed, bout 3 mph, engine, and blades never changed pitch, no bogging down. Test cut of 3 in set at 1.75 and zipped through it quickly and cleanly.
Will surmise, this kit allowed engine efficiency of air intake, as it never did alter sound when loaded up.
Torque must be the benefit the AF contributed.
I would absolutely recommend making this a must have improvement.