My guild is currently progressing in aq40. I kept my previous MD/Ruin spec which have me consistantly performing better than similarly geared warlocks and keeping up with most mages in BWL. However since we have been progressing in AQ40 I have noticed that other warlocks seem to be performing better than I am. Is there a more favorable build than MD/Ruin for AQ40 (and soon Naxx) and what kind of strategies do other warlock use to maximise their damage output.

MD/Ruin was destroyed in the last patch.

Take SM/Ruin if you want to spam and be able to provide an imp. Take my personal favorite the trispec (7/21/21+2, also called DS/Ruin), which I personally think is the best raiding build, but you are cripppled if you are required to provide an imp.

Amazingly, Conflag builds can put out equivalent level damage as well. I went NF/Conflag for C'thun, and I truly enjoy it. Most fights are not aggro sensitive for one reason or another, so you have a cheap nuke that hits hard to spam (SP) and heavy burst dmg as well. You'll use more consumables than DS/Ruin and SM/Ruin, but it's an awesome choice. I adore the extra range I get on affliction (NF is the most overrated talent of all time) which can mean a lot as well on the highly mobile fights to be found (Skeram, Sartura, Emps, C'thun, Ouro).

I'll agree 100% on the fact that MD/Ruin was obliterated in it's utility last patch, but I think the 7/21/21+2 build is the most versatile of what is available. Though you lose out on the -threat reduction of imp, you are still providing the tank with an improved blood pact instead of a gimped one. Your healthstones scale out a bit better and on fights where you're not on imp detail, you provide a longevity that is not otherwise accessible to warlocks without DS or an ample supply of willing healers.

Some people are also not aware that SM only applies to base damage of your spell, it's not a percentage applied on top of your damage gear. So the benefit you 'think' (sometimes) you're getting is really minimal and hardly worth the 30 talent points. I personally put the remaining 2 in the 7/21/21 into suppression, so I know my corruptions will not get resisted.

They changed SM like 6-8 months ago to include +damage gear.

For AQ40 and Naxx, NF/CF is my preferred spec. And though I still hold that DS/Ruin (I've always done it 9/21/21) is the best spec for raiding boss encounters, there are only a few fights where it's immensely superior - Patchwerk and Loatheb being the big ones in Naxx (among those I've tried or have a good working knowledge about). NF/CF, on the other hand, is MUCH better for almost any trash, and making C'Thun a much more fun fight IMO.

Since AQ40 came out they've introduced a LOT of encounters that (thankfully) get the hell away from threat management and tank n' spank look more towards mobility, burst damage, high DPS and lastability. Because of this (and the DS+MD nerf) MD/Ruin has been all but phased out.

A NF/Conflag build has mobility, burst damage and high DPS by the bucketload, while DS/Ruin gives you the option of what you want to excel at. If you want DPS, sac the Succubus. If you wan't lastability, sac the VW/FH.

Oh god, this old myth just refuses to die, doesn't it? Sigh.

I keep seeing it pop up and since I'm not a fan of SM, I've never tested it. It's my understanding it wasn't a myth.

SM not applying to gear is not myth. It is, however, history.

And compared to SM/Ruin or DS/Ruin, NF/CF excels in fights where burst damage matters. And there are a lot more of those in AQ40 and Naxx than MC/BWL.

NF/CF is situationally good DPS, while SM/Ruin is overall the better spec, in naxx and AQ........Imo.

There are a lot of spots in Aq40 where there are many adds that are dottable, even as MD/Ruin nothing stops you from at least throwing agony on everything with 6 legs. Maybe they are hellfiring when you rain of fire? Aoe makes a huge difference in DPS in Aq40. Are you looking at the damage meters to see how are they beating you? In Damagemeters 5.0 (actually I think the option started earlier versions) if you choose parse all events you can hoover your mouse and hold the ctrl key to see the damage break down of there spells, i.e how many shadowbolts they cast their average damage and total damage, same with your other spells. If you see that they are casting the same spells as you in the same proportion is there average shadow bolt higher? Maybe they have choosen better gear upgrades.

Jumping to a new spec isn't the solution to every DPS problem. I am MD/Ruin and I generally top the damage meters for locks and I am almost always in top 10 for DPS except in encounters where I am tanking (ouro, twin emps) or a few like the princess and satura where I am trying to pull aggro with constatn dots to pull aggro after fears and whirlwinds. Any tank and spank encounters I can make the top 5 for DPS. Also know what upgrades are worth it for you class, i.e. if your gearing up doomcaller, the shoulders and head are huge upgrades over t2 where the legs/boots and robes are minor upgrades so get those last. Are you concentrating on +hit or +damage gear? What are the other locks concentrating on?