[Death Knight] Blood DPS, DRW Discussion

There was a discussion the other day about Dancing Rune Weapon and its viability for Blood dps, compared to Frost subspec with Improved Icy Talons or Unholy subspec with Unholy Blight.
While I was convinced that DRWspec will outperform both others, I set out to try to get some theorycrafting done. I have played Blood dps for quite a long time, before 3.3. Some of the stats I bring up might be out of date, so correct me where I'm wrong.

Base Blood dps spec: This
Some of the talents can be switched around a bit (Bloodworms) but this is the basic framework of the blood dps.
The Unholy Blight talent tree is pretty easy to make, compared to base blood dps tree. Unholy Blight would be taken instead of DRW, with the glyph changed as well from DRW > UB
The Frost subspec is costlier in terms of talents, and you will have to forgo Blood Gorged in lieu of weak(er) frost talents, in order to get to Improved Icy Talons. The best build I have been able to come up with is this one.
Note that with Annihilation, Obliterate might take the place of Death Strike in DPS rotations, allowing you to free up another point from Improved Death Strike, however, also note that Might of Mograine no longer affects Obliterate, so I am unsure which of the two would pull ahead. Also, I think it might be a toss-up for Icy Touch glyph vs. Ghoul glyph, did not do any real calculations on that one, though I assume the dps difference to be very small.

Now let's get to the heart of the matter at hand: comparing the specs.

51/0/20: Based on my memory from this spec, Heart Strike and Melee were top dmg, each about 23% of total, with DS and DC around 19%, each disease about 4% and Necrosis + BCB around 1% per talent point, or ~8% combined. This is a rough idea of the proportions as I remember them.
YMMV. This was what I remember of T9 content and in T9 gear. Especially with different values of ArP the ratio's would shift, but unfortunately this is all I have. If your numbers differ greatly from these, please reply with your observations and I will edit this post.

Consider the use of DRW 10 seconds after each CD (time for RP generation if necessary, or averaged time waiting for a burn phase), this would mean (glyphed) 17s/100s or 17% uptime of +50% damage = 8.5% DPS, at the cost of 1.5 DC but winning .75 seconds of GCD. I know people are not machines with no latency, and this might be an oversimplification, however, it does not seem unreasonable to count at least 5% dps for this talent, especially considering the added benefit of being able to use it during a burn phase (during Bloodlust, or Icehowl crash, XT heart, etc).

50/0/21: Unholy Blight gives +10% (+14% glyphed) increase in damage of Death Coil. Given the numbers I posted above, 19% * 1.14 = 21.66, or 2.66% dps increase. This is clearly inferior to DRW even in the most optimistic of scenario's. The only advantage I can see over DRW would be the added ranged dps for when the boss is out of melee range (Onyxia p2).

44/26/0: The frost Subspec is a lot more challenging to theorycraft on. Initially I dismissed the idea outright considering the large investment in (weak) frost talents and loss of some very decent Unholy talents. However, for rDPS it might pay off if (and only if) you're missing WF totem.
The loss in Unholy talents I guesstimate to be about 13% if not more, with Endless Winter being about equal to Ravenous Dead, 8% from BCB and Necrosis, and another 5% from having to reapply diseases more often (Epidemic) and the lost hit for DC (Virulence). The loss of Blood Gorged would be around ~15% (?) at low levels of ArP.
The gains in frost would be +20% raid melee haste, additional +5% personal melee and spell haste (allowing around one additional DC every minute), higher crit chance (near 100% because of Killing Machine, and not using it on any other abilities) and damage on Icy Touch (which would partly negate the dps loss from having to reapply), +10% dmg on diseases and DC (Black Ice), and additional RP generation.
I believe this spec might surpass 51/0/20, in a melee heavy raid and when missing WF totem. However, it begs the question: why not go for a full Frost build? I am absolutely convinced it would outdo this spec in pDPS, and raid bonus would be identical (neglecting the loss of Hysteria). Even an Unholy build such as this would be better by far than Blood with Frost.

Conclusion: My numbers are not completely reliable so take things with a grain of salt, however it would seem that DRW is an underappreciated gem in the Blood tree, and definately worth picking up over the possible alternatives.

Wall of Text is made of Text