Are you sure that pets benefit from player's expertise? From my understanding, if the player is hit caped, then the pet is exp and hit caped.
That is correct. From the patch notes:
All pets now receive 40% of their master's resilience and 100% of their master's spell penetration. In addition, if a player is at their appropriate spell hit chance or hit chance maximum, their pet will be at the maximum for spell hit chance, hit chance, and expertise. If they are below the maximum, their pet will be proportionately below those maximums.
I want to point out that patch 3.2.2 was announced (the one with the Onyxia's Lair revamp and more). This could mean a fix for the Scourge Strike nerf which made Obliterate better. Therefore, I think we should be careful that we don't stray too far from the regular idea of Unholy of not stacking ArP - this is all theory-based though, so who knows.
Just wanted to put it out there. Otherwise, the build's been working nice for me and mostly everyone else as stated a few pages ago.
Bandit's is indeed superior, it just has never dropped for me. My trinket luck is just horrid. It's like Banner or Mirror. Hoping Algalon drops either [Dark Matter] or [Comet's Trail] soon, but until that I'm kinda stuck with Banner (which is actually pretty amazing for a five man trinket, but yeah, doesn't compare to twenty-five man stuff). Unless I can find a way to drop enough hit to make the Yogg trinket usable, but I don't see that being doable.
T7 4 piece is good - it always has been - but it still isn't worth using over T8. The T7 4p causes you to generate 170 RP per 20 seconds instead of 150 RP per 20. That's a 13.333% increase in how many DCs you can throw (and, as such, how much damage your UB deals). The T8 2p, on the other hand, is a flat 15% increase in your DC (and thus UB) damage, meaning it is easily superior (plus, it scales with extra DCs from AMS RP). This, in addition to the higher stats, makes T8 still way above it.
Edit - Don't know how to make the Wowhead link show the Dark Matter trinket instead of the quest item, but whatever ><.
I'm going with the 17/54 but I'm curious to points being spent in 2/2 Chill of the Grave. Since people are saying to use Obliterate over any skill relating to RP, wouldn't it be better to have 3/3 Subersion for OB crit instead ?
Seeing there is none, I calculated Unholy stat values using Kahorie's DK Simulator. I didn't used EP but normal simulations and manual calculations. Gear used is ilvl245 quality - base stats were: 255.7 dps, 3.6 speed, 2000 str, 150 agi, 14000 armor, 250 ap, 263 hit, 900 crit, 100 haste, 500 arp, 164 exp, Virulence sigil.
For 4xT9 I assumed that WP will proc it and it won't have any cooldown so it most likely is little high (and too high if WP won't double crit). I also have no idea why crit and AGI is valued less in OB build. Also haste value should be closer in both builds. T9 bonuses seems to be OP so I would expect nerfs on them (internal cooldown on 2xT9 and sigil probably incoming).
Treat numbers above only as general direction until someone count them more properly.
Considering the ilvl-difference between SoV and SoVH and especially vs SoA the noticable-but-not-huge dps boost does not at all deserve a nerf if you ask me.
About the crit and agi rating being lower in 3/13/55 it's obviously because you pick up Subversion giving you 9% higher chance to crit. The higher your innate crit rating is, the lower the value of additional crit. It's simple really.
EDIT: I'm actually sceptic about your numbers, especially just crit rating being on 1.9 EPAP in the 17/54 spec, I really don't see how crit can be worth more going from SS to Obli that has so much more talents boosting it's critchance already.
Those numbers all make a lot of sense, and are greatly appreciated.
The one thing I don't quite understand, however, is the change in haste's value. Auto-attack is the same portion of your damage as it's always been, more or less. The only talent 12/0/59 has affecting it which 3/13/55 (or 0/17/54) does not have is Bladed Armor, and I can't see that making up for a ~20% difference in value. Unless there is something obvious I'm missing?
And, to the above, it's not as simple as just buffing SS back up (they did have a reason - PvP ones - for nerfing it in the first place). Although using Obl seems odd and is contrary to the intended playstyle, it is still perfectly viable DPS wise, so I doubt it's a high priority. Besides, it also happens to make ArP more attractive for Unholy, something they've been wanting. The fact that they don't have a solution quite yet isn't all that surprising, and isn't that big of a deal.
Edit: Also, the Sigil already has an icd (and I would imagine 2p t9 does as well). Admittedly, yes, the icd is shorter than the duration, so you can still have 90%+ uptime on a stationary fight, but it is there. Really though, Vengeful Heart to Virulence is no larger an upgrade than Awareness to Vengeful Heart. Sigils have always been very strong - stronger than guns/bows/wands. That strength, however, comes at the cost of not having many options for that slot, and not being able to stack a specific stat from it if you must.