I disagree.
The narrow band doesnt tell u squat. And for ALL tuning applications you need a wideband. Its not only the forced induction guys who need it. The forced induction guys just have a much smaller amount of "wiggle room" to get it right. But N/A, turbo, supercharger, nitrous, etc.....u want to know exactly where you are at.
And besides, since he doesnt need this maf, he can put that $70 towards a $200 wideband setup.