Edit: Hopefully the charts are at least readable now, although very ugly.
Ok I have done a lot more frame-by-frame research and have a lot of conclusions.
From the time it can first hit to the time it cannot hit is exactly 2 seconds, however cast time to full animation stop is longer, there is time at the beginning and end where it cannot proc.
Meaning the breakpoints are more straight forward:
Because it stays out for 2 seconds, there is an obvious relationship of 2x your APS, however the animations don't match the ability to proc, I was counting animations before and that was a mistake. Higher attack speeds don't necessarily make it so you can have more out at a time, but they do give you more procs per second as there is a lot of wiggle room. From what I can see, more attack speed is better and there may not be significant breakpoints at all.
It ticks 4 times per second (8 ticks per cast, one for each "step" the lightning guy takes) regardless of APS. Each tick releases any number of lightning strikes against all nearby targets.
I tested vs up to ten targets, there does not appear to be ANY limit to concurrent targets, all of them were hit any time the LL ticked and was in range.
Example single target hit count for a normal size mob.
5 times at melee range (the LL gets out of range for the last 3 ticks
8 times if at perfect distance (all 8 ticks are in range at this distance http://imgur.com/YdAF257 )
1 time if they are right behind you, only the first tick is in range
50% crit, 20 APoC, Melee range (not optimal range).
These numbers are PER TARGET
APS = Attacks per second
Hit/Sec = The amount of times you will hit enemies per second
APoC/Sec = The number of Arcane power points you will gain per second from 20 Arcane power on crit.
PrdgyAP/Sec = The number of Arcane power points you will gain per second from Prodigy passive.
CM/Sec = The number of seconds Critical mass will reduce your cooldowns by per second.
Proc/Sec = Multiplier for Life On Hit per second and Arcane Dynamo Flashes per second
Please note, these values are only 5/8 the maximum value possible multiplier, because melee range is not optimal. The Maximum (perfect aim) values are here:
Notable exceptions: Missile Dampening changes the duration for living lightning from 2 seconds to 4 seconds, but does not change its proc rate. The effect is the exact same as DOUBLING your attack speed. Thanks Sokahr.
Edited by Shaggy#1317 on 2/8/2013 10:39 AM PST