What's the difference between a full and half twist? (aside from the obvious)

The link below describes it a bit more. For me the full throttle is ok, except when someone was trying to help me with a mechanical problem (Bent seat post....another story), and he lifted on the throttle, which broke the little plastic tabs inside which hold it on the handlebar. I was able to glue them, so I am gonna get a replacement. The half twist I imagine would allow you kind of hold the throttle with 2 fingers, with the other 2 on the stationary side for a cheap cruise control.

http://ebikes.ca/store/#Throttles