My car has 66000 miles, and the Dryflow has been in use the from the first 500 miles to date. I recall the intake sounding louder and overall throttle response is improved. Gas mileage may improve with a light foot.
It is a pleated design but does not use any oil which can foul sensors and maf.
I have been very happy with the Dryflow.
I also popped out the plastic restrictor that surrounds the lower hood latch. This is the source of the air inlet for the stock 2.5 NA airbox. Definitely louder and better air flow into the intake.
I was able to confirm with my dealer that the replacement cylinder head that was installed on my 2018 is a redesigned part to correct the "porous casting" of the original.
The chassis steel and welds are not great conductors. Thick copper wire has much lower resistance. When connected to well chosen grounding points there can be a benefit.
A obvious grounding point on my 2018 can be found by removing the plastic cover on the engine revealing a factory grounding...
Damn, the crack could happen again. I only drive about 5000 miles a year now in retirement with 63k on the odometer. I will be selling my car at around 90k to avoid a crack, although this will be years down the road.
Somewhere upthread I though I saw a comment that the cylinder head being used for replacement on my 2018 head that cracked in February have not been revised with a better improved casting. I seem to remember from either Mazda USA or the dealer service writer stated that the head had been updated...