What are the pros and cons of MAF vs speed density tuning?

Here is what the documentation says. Each point links to its source; tables and names vary by computer, operating system and tuning software.

• E38; LS Gen III/IV; 1997-2013: Speed density tuning models airflow from a three-dimensional volumetric efficiency table indexed by manifold absolute pressure and RPM rather than measuring it directly. (High Performance Academy)
• E38; LS Gen III/IV; 1997-2013: The MAF sensor has some latency under transient conditions such as sharp throttle openings, which is why GM added a speed density subsystem to complement it. (High Performance Academy)
• E38, E67; LS Gen IV; 2005-2013: LS ECMs run a hybrid fueling mode that can be strictly mass airflow, a blend of MAF and speed density, or purely speed density, depending on operating conditions. (LSX Magazine)
• LS Gen III/IV; 1997-2013: A speed density tune is configured so the vehicle fuels from the VE/VVE tables instead of the MAF; on HP Tuners a 0 or 1 in the MAF frequency fail-high diagnostic indicates the car is set up this way. (PCM of NC)

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