Also, is the 150 dps factoring in a pre-pot indestructible pot that won't happen anymore? Assuming your single target spec is something like 2/15/54.

Isnt Morbidity value increase aswell because of black ice?

Well, necrosis will also, with Black Ice+Icy talons..

Whoops, I've made a mistake with the 3.3.3 talent build. Subversion was still turned on. Blood is still the best sub-spec for Unholy.

Fishing for Cinderglacier procs will mean, in almost every situation, swapping in your old weapon with the cinderglacier enchant, thats going to be a DPS loss. You also lose at least two global cooldowns (for the weapon swaps) even if you are lucky and get it on the first swap, and, assuming you have a rogue sitting on his ToTT waiting to cast it on you, whatever cooldowns it takes between you yelling on vent "Hey, ToTT me now" and him casting it since you can't use any PS-IT or SS in that time without burning your Cinderglacier proc. You also have to subtract from the raid the DPS the rogue loses by saving his ToTT until you get the proc.

Just for curiosity how many times have you managed to roll two Cinderglacierd / ToTTed diseases for an entire fight? Can you link a log where it was successfully managed by anyone? I just suspect that it is a theoretical possibility but a practical nonentity.

Look through the top 20 unholy DK parses for Festergut on wow meters, every single one has 10-12 casts each of PS-IT. If glyph of disease was such a big DPS increase on single target wouldn't it stand to reason that at least one of the top 20 parses would use it? I don't think its a case of people looking at sims and undervaluing GoD, it's a case of people looking at reality and seeing its actual value. On Saurfang for example you will see plenty top parses with DKs rolling a single ToTT for the entire fight so obviously there are plenty of DKs capable of doing this, but not a single one of the top parses on Festergut, the only real single target fight in the game shows this. If the sims put it as a DPS loss, and the parses put it as a DPS loss then I would say the onus is on the person claiming it is a DPS gain single target to do the proving.

Again, you are not just giving up a PS + IT + BS for a SS + Pest, you also lose 5 runic power in that exchange, so you are giving up PS + IT + BS + 12.5% of a DC SS + Pest. On any parses I look at that works out to be a slight DPS loss.

Even on AoE fights for the most part it will be impossible to roll a ToTT boosted diseases for any length of time. Saurfang is probably the exception in ICC (ToC has a couple of fights where its practical), anytime you are switching to adds it is almost certain your original boosted diseases will fall off at some point. either that or you end up having to use pestilence more often than you should to keep the diseases rolling with the associated loss of BSes and DPS loss that would entail.

Without ToTT and perfect disease rolling never letting your diseases drop on a single target it will end up as a DPS loss whatever way I look at it.

I can't see disease twisting as a DPS gain either. No matter how you cut it you are turning your 20 second rotation into a 21 second rotation to gain 1 tick on 1 disease. That means giving up 5% of your special ability damage. Since most Unholy DKs will have about 40% of their DPS as special ability damage thats a 2% dps loss. On your diseases you go from 12 ticks per 20 seconds to 13 ticks per 21 seconds. Thats an increase of (13 / 12 * 20 / 21) = ~3.2% in your disease damage. You are losing 2% of your overall damage (by losing 5% of your special ability usage due to rotation stretching) to gain 3.2% in part of your damage. Your diseases would have to be accounting for over 60% of your overall damage for that to work out as a DPS gain, in short, it is a DPS loss.

Think about it logically, there is literally no way your first cast disease can tick 7 times per rotation unless that rotation is 21 seconds in length. In fact, since your rotation is becoming 21 seconds anyway with disease twisting you would be better served just waiting the extra second and not clipping either disease (though it would still be a DPS loss).

Take for example the rotation:

It looks nice but the reality is it becomes:

You leak a GCD everytime you swap diseases. There is no way around this. I think you are imagining it would work something like:

But it can't work, for that to happen your Unholy rune would have to come off cooldown 3 seconds early when you switch back to PS-IT. That is not going to happen.

You could potentially achieve something similar if you delayed the start of the second rotation by 1 second and abused the two second rule. Then those runes would effectively come off cooldown 9 seconds after you use them. You would basically be alternating between a 21 second rotation and a 19 second rotation abusing the two second rule to make the latter possible. If you do that then you could get both diseases ticking 7 times on the first rotation and 6 on the second but the margin for error would be pretty tight. You still would not disease twist as it is listed here though, anytime you go from PS-IT to IT-PS your first rune will be getting used 3 seconds after it first came off cooldown, you leak a GCD every time and that stretches your rotation by a GCD and will be a hefty DPS loss.