Dark/Dark to proc or not to proc that is the question?

I been reading a lot of posts about dark control ability to take a lot of procs in particular living shadow but have not managed to get a definitive answer to how effective they are in game.

so I would like to get everyone in game experience on the following proc slotted powers and advise if it is worth doing.

DARK GRASP - ATIO proc,clouded senses proc, unbreakable restraints proc, ghost widow proc + HO Acc/mez x 2

living shadow - acc/end x2 + gravity anchor proc, clouded sense proc, posi proc, and trap of hunter proc vs 5 x posi + another proc

Tar patch - slow proc (pacing of turtle I think)

haunt - build up proc vs clouded senses proc

shadow field - how does proc work in this in general and which are the best?

Depends on your build and what are you aiming for. Ill tell you what Im doing, but YMMV

Dark Grasp gets basilisk + Hami Acc/dam + Dam IO, I want the recharge
Living shadows gets 2x acc/end , 4x damage procs (not ATO)
Tar Patch is good enough for me with 1 recharge, no proc needed
Haunt could use the build up proc, but I 6slotted it with Expedient Reinforcement
Shadow field gets 4x basilisk + lockdown, or 5xpurple + lockdown
Heart of darkness gets 6x S.ATO

Just think of them as a flat damage added enhancement for most powers. Procs do not benefit from containment. Orange/yellow procs will add 14.35 damage per cast on average. Purple procs will add 37.5. They don't care if the power is single target or aoe. In persistent powers, such as shadow field, they will have a chance to proc every 10s.
We're not really sure yet exactly how ATOs work in aoe powers (their proc chance is reduced by some amount), but in single target powers their chance to proc would be base recharge/(60/ppm) which means if you put the superior ATO in dark grasp you'll on average get 71.4 per cast, and in shadowy binds it'll be 37.5.
Shadowy binds and dark grasp, with containment, will gain about 26 damage from a damage IO, meaning ato>purple proc>damage io>other procs. Living shadows on the other hand will only get about 10.12 damage from a damage IO w/ containment, meaning procs come before damage enhancements.

Haunt takes a couple more steps. According to city of data, they have one attack that has a 3s recharge and hits for 46.72 damage. The buildup proc has a 17% chance, lasts for 5.25 seconds, and adds 64% damage. Because of the recharge, we can say that they will only get a maximum of 1 attack off with buildup, doing an additional 29.9 damage. With a 17% chance to proc, that means about 5 extra damage per attack on average. At this point, it's clear that clouded senses is better, even before considering their fear attack and ai that might cause them to waste it.
Umbral beast on the other hand has a higher base damage but lacks -to hit/fear on a lot of its attacks, meaning buildup will be more valuable than the other available procs.

tar patch - most people, myself included, will tell you not to use -recharge procs in anything. I use the impeded swiftness proc in it since my build is heavy enough on global recharge that recharge enhancements are of negligible value.

shadow field - It applies an 8 second hold initially, and for every 0.5 seconds an enemy is in the patch it had a 5% chance to apply a 4s hold. I put 4 basilisk's gaze and a lockdown proc in it. If I had the spare slots, I'd add a -to hit enhancement. Since it has such a long recharge I wouldn't bother with damage procs.

Thanks for the the insightful response. It's really helped decide on how to slot my powers.

I slotted the ATIO into Dark grasp and I am pleasantly surprised how often it procs - it feels like it procs every other use! It's definitely staying in there even if it means I lose the full set defence bonus.
I read in the general thread that the store bought IOs procs rate are also based on the ATIO proc formula so I might invest in the chance for build up and ghost widow proc!

Cheers

I actually don't have any damage slotted in Dark Grasp or Living Shadows, in fact I have no damage slotted in any powers other than my pets and I have not had any issues with damage so far. I plan on getting Intuition Radial Paragon and Spectral Total Radial Conversion later. I may have 2 or 3 slots I'm thinking about moving around.

I'm running at 0/4 in the DA arcs, as well as against Arachnos, Freaks, Carnies and Rikti and nudging my way up slowly.

Dark Blast: 4 slotted Basilisk's Gaze

Living Shadows: 5 Slotted Grav Anchor (May use one of my extra slots)

Shadow Field: 5 Slotted Unbreakable Constraint (May eventually 6 slot with a Lockdown proc)

Tar Patch: 2 slotted 1 recharge, 1 slow (May remove 1 slot)

Haunt: 6 slotted, 4 Call to Arms 2 Recharge

Has anyone tried slotting the build up pet proc in umbral beast? if so how effective is it and is it worth it?

Cheers