That is a nice improvement in efficiency. NG was my go to filter for a while. The cost is at least as much as the M1 filter for me, so it would have to go for as many miles, for it to make sense for me.
Is that chart in post #3 correct? I thought they always had silicone ADBVs.
At any rate, is there a mileage limit on the box? I thought either the box or the website said 10,000 miles back when I was using them, but I might be misremembering.