I just switched from deep affliction to deep destruction and I just can't come to grips with spell priorities and how to increase my DPS. I feel that I lost a huge chunk of DPS in the switch and am now trying to find out why this is. My priorities are as follows:

Immolate, conflagrate, chaos bolt, corr, coa and Incinerate as filler.
I barely beat 4k DPS on Patchwerk last night bu most of the fights I was sub 3k and even down to 2k. I must be doing something terribly wrong here and I can't figure out what it is.

I don't have a log parse yet as I could not access WWS or Wowmeters at all last night.

Somehow I feel that affliction with Haunt was easier to handle than this but it may be down to experience of the talent build. Any hints on how to improve are welcome

Yes, on live. I just could not imagine the difference would be so huge.

Imo, Quartz is the most important addon for Destruction, and you need to make sure that you are always casting spells back to back. This is tricky at the beginning because of Backdraft.

The rotation becomes significantly easier if you do this: always go Immo > Chaos Bolt > Conflagrate. You only need to watch for the 3 dots, since you only cast CB and Conflag after Immolate. This is a good way to get used to Destruction, and you avoid casting different spells under Backdraft (you'll always be casting Incinerated when you have that buff), which makes it easier to keep chain casting, If you need to life tap, try to do it before you cast Immolate, so that both Immolate and CB benefit from the 4pt7 set bonus. Once you are used to this rotation, then you can try to keep Chaos Bolt and Conflagrate on cooldown. If you feel like you got lost in the rotation completely, you can fall back to the easier rotation. In my experience the dps difference between the 2 rotations is not very significant (on live; on the PTR the dps difference between the 2 rotations is huge, because of all the buffs to Conflag, so you'll eventually want to move to the harder rotation; but on the PTR keeping Conflag and CB on cooldown is actually quite easy because you no longer use CoA and Corr). In any case, I always cast a spell between Immo and Conflag, because it's not possible to queue a Conflag on an Immolate.

You can also use Flame Caps.
Hope this helps.

Latest patchwerk parse, Unholy Power/ChaosBolt spec(0/20/51), Glyphed Immo, Imp, Conflag:
Wow Web Stats

Having played FG/Ember, and then Haunt/Ruin earlier in the expansion, I figured I'd try out a deep destro spec. Some of the deep destro talents are rather weak, so I opted to give my imp some juice, and skip FnB entirely.
Can't say I'm disappointed, altho it took a while getting used to the spec, since the priority/rotation can become very staggered at times.

Oh and btw, no speed/wild magic, no food buff or flask. As far as i recall atleast.

I tend to find destro does pretty poorly on thaddius, then again maybe I just suck

I always have issues with the damned imp never making it onto the next ledge and have to quickly resummon on the platform.

WWS

Hes affliction. At the moment on live, affliction is a far superior spec.

Pyroclasm vs Empwered Imp vs Fire & Brimstone

I tend to enjoy a nice heroic or Wintergrasp stomp while main specced. Also I'm addicted to Shadowfury. So my goal for deep destro was to figure out which talent points contributed the least to DPS so I could spec for fun/utility talents like Fel Dom, Soul Link, Shadowfury, Destructive Reach, or even Nether Protection!

I didnt get too scientific about it. I downloaded Simcraft and ran different specs. I post an MMO link and the average DPS from Simcraft with notes.

Baseline 0/13/58
6592 DPS (32% Pyroclasm Uptime in the Sim, while Imp Firebolt was 9% of Damage and critting 18% of the time)

Smiple figuring at this point says Pyroclasm is about 3 points for 2% total DPS, while Empowered Imp is 3 points for 1.5% DPS (Firebolt) + ~4% player crit.

0/13/58 - 3/3 Empowered Imp, 5/5 Fire and Brimstone, 0/3 Pyroclasm
6485 DPS - As expected, lose about 40 DPS (<1%) per point.

0/13/58 - 0/3 Empowered Imp, 5/5 Fire and Brimstone, 3/3 Pyroclasm
~6420 DPS A bit wobbly, but about 60 DPS lost (1%) per point.

0/13/58 - 3/3 Empowered Imp, 2/5 Fire and Brimstone, 3/3 Pyroclasm
~6450 DPS - Even though I love seeing massive Conlflagrate numbers 1 point = ~50 DPS (<1%)

So as a rule of thumb Pyroclasm, Emp Imp, and Fire and Brimstone are each about 1% DPS. Pryo provides the least DPS, F+B next, and Emp Imp. If I need more than 3 points, F+B and Imp are close enough that between the two I'll probably keep F+B for mondo crits on players, trash, and adds.

No, Ur-Vile's post is relevant. The Destro spec used by Simcraft in the post-3.1 Simulation thread doesn't use Replenishment, Destructive Reach and Shadowfury, all of which are interesting for PVE. We want to know which talents are weakest if we want to make compromises.

its possible to pick up replenishment and still keep most of the candy by simply not taking supression, however how large is the marginal loss here, compared to taking the talents out of previously mentioned weakest spells?
It is an interesting question indeed.

If your raid is not going to have replenishment, it is better to drop suppression and take ISL. Replenishment is a mandatory buff and is absolutely necessary for your raid. However, destruction warlocks lose more key talents than other specs containing replenishment and should be last on the priority list of specs forced to pick it up.

I was putting together a destro spec that picks up all the possible imp buffs except Unholy Power, and then it came time to decide on glyphs and destro looks like it has a ton of awesome glyphs. I feel glyphing CB and conflag are all but given, as it puts CB on the same CD as conflag, and conflag's usefulness is well-known. My question is what glyph is best for the last slot: glyph of imp, glyph of immolate, or glyph of incinerate?