Makis, I don't understand your thinking. 1/4 turn is already more than I care for, why on earth would I want 1/3 or 1/2? That adds even more roll to the throttle.
I want a little less so I don't have to move my fingers of my brake lever.
The more you need to twist the throttle to a full open position, the smaller acceleration fragments you get and so the better you control the throttle opening inside a curve.
Riding around in public roads, I found out that the 1/4 throttle twist sure makes my fingers leave the brake lever less than a 1/3 but have been always very nervous trying to give A LITTLE throttle while leaning inside a curve. The rear wheel becomes stuttering when you tryto open the throttle from 0 twist to something (2-3 degrees).
I guess with the 1/6 that effect will be multiplied while the fingers will be more close to the lever all the time.
It has totally to do with each one's driving style and what feels more important to him while driving.
If I want to hit the brakes, I instantly lift my hand off the throttle tube by half an inch, the throttle comes back to zero and then grab the brake lever and the throttle tube back to squeeze....that I can do whether I have a 1/6 tube or a 1/3.
They both will come back to zero position if I lift my hand off them......however, they will not give me the same detailed throttle opening hence the same FINE throttle control over the rear wheel inside a curve when half of my butt is hangin' over the seat