I have noticed that the particle and sprite performance test on iPad return strange results.
A size=4 pixels

C size= 32 pixels

Conclusion If you is using "little" particles then PointParticleSystem is faster, but if you are using big particles (size>16) then QuadParticleSystem is faster than PointParticleSystem.
For example:
8 bits, PointSystem, 4 pixels -> faster method
8 bits, PointSystem, 32 pixels -> slower method
and
32 bits, QuadSystem, 4 pixels -> slower method
32 bits, QuadSystem, 32 pixels -> faster method
WTF??????