This is my perspective as someone who picked up DRK at the end of SB and is going through the MSQ as DRK. The job definitely feels different. I like it, but a couple of things just don't make that much sense to me.
Mostly, Dark Missionary. A 10% magic reduction for the party seems nice, but then you start looking at the numbers. It's only 10% (basically another Reprisal), so it's very unlikely to mitigate a meaningful amount, which is basically a few auto-regen ticks. It's kinda just there and doesn't affect the greatest issue that DRK has, the very high MP cost compared to how hard it is to generate MP outside of the burst window.
In my time in SB you could regain almost all MP in a few rotations and abilities, but not here. Flood and Edge are clearly meant to weave in between the rotation to break it up, but with their high cost it can only be done a few times before needing to have several 1-2-3 rotations to do another. TBN is also an issue as it also uses a ton of MP and does...not that much really. It's a strong shield like it was before, but it doesn't give the player the defensive options that SB had because it is more difficult to generate MP, so ultimately if you want to spam it, you need to forgo edge/flood, thus making the rotation more monotonous.
AoE rotation is much the same, it's two buttons over and over with the occasional Quietus to break it up. Quietus is now just damage, nothing else. I would like to see Quietus put into the combo, have it generate something and have Abyssal Drain cost a resource (probably blood). This would give the player a better defensive kit while still incorporating the SB AD play.
So yeah, my greatest complaint is that MP costs are too high compared how much abilities cost, and how little the abilities affect each other for their purpose.
That being said, I am still having fun, so it's a solid B from me. It's not outstanding, but it's not unplayable.