MAFs were essentially a replacement for VAMs which are highly restrictive, mechanical, large, and hard to tune, even for production. The MAF, or hot-wire, is much smaller, lighter, and easier to produce. MAP sensors are the way to go (as silver03p5 suggested), however. They're small, non obtrusive, allow shorter TB to Filter piping, and so on. Basically, it's a pressure transducer. Air pressure (with respect to atmosphere) + temperature + appropriate ECU maps = a running engine (basically).
