Looking around the webs and Reddit and such I found a lot of slightly wrong and/or confusing information about the recent toggle abilities efficiency/duration change. The basics are increase duration increases the time between when each drain "tick" hits. Increasing efficiency reduces the cost of each drain "tick".
First I'll do an example then I give the maths behind how this works. Let's take a toggle power that has a base drain of 2 energy per second.
If you increase duration only