youd have to admit theres a big diffence in engine charachteristic between the a-12 and a-15, Yes?

well i see the a-14 as the inbetweener cause the a-12 will rev like all hell and go if you keep the revs up there, but down low its a slug

The a-15 exactly the opposite it launches from low revs and never really reaches high revs

the a-14 gives a happy medium where you can use torque down low but also let it scream

it obviously depends on how the engine is built (cam choosen ect. ect.) but in general thats the way i look at it.