Nsfw is right. And the thing is that the tuners/shops doing this chit should know what parameters to look at. But they don't and I can't recall any header test done on here with mafv plots (except mine, which wasn't a header test).
Its really easy to tune a car conservatively on one part then add 1* of timing on another part and pick up 10whp. So pretty much all results are skeptical to me unless all the data is posted.