So basically you are another know-it-all noob like Plan-B?
You come here for advice - we give it to you... You then proceed to tell you that, sadly, you are misinformed.
Now we are talking rubbish?
A 1.5 was diff is TOTALLY predictable. Have you even driven a car with one? I have, many times.
I also OWN a car with a 2-way mech locker. I can tell you now neither is more or less predictable than the other.
Such a statement clearly shows you don't even know the dynamics behind how it works and the effects of having either.
If I had a choice, I wouldn't have a 2-way in my car. I'd have 1.5
However the factory HR31 diff is a 2-way, and rebuilt is tough as guts, so it was the much cheaper & faster option at the time.
I've had the HR31 kick out UNPREDICTABLY in the wet with the 2-way. I can assure you whilst it looks pretty fken cool, going downhill with your rear end @ a 45 degree angle in the wet is certainly brown undies moments.