I don't think speed density is totally obsolete, some new vehicles (performance vehicle) have it from the factory.
MAF does work great but is typically found on OEM single air snorkel plenum intake tubes, which will lock you into the diameter of the MAF and surrounding pipe as it affects flow. Change cold air intakes on a Mustang, get a CEL. and go get a new tune. It doesn't lend itself to an 8-stack, or a round air cleaner setup. I bookmarked this last year as it summed up a lot of the issues I ran into doing ever changing mods to my Stang and 3 engines later...
https://www.mishimoto.com/engineerin...speed-density/