I am interested in this as well. I tried doing a seperate build for mythic plus and i ran a few today. I was messing around with different talents inbetween every run and my stats were 50-51% crit, 9-10%haste, 18-20% mastery and 2-3% versa. I was trying everything, different gear, different talents, different rotations, different legendaries but I always ended up only doing around 350k dps total for the entire dungeon. I don't get it, at 880 i should be doing a lot more i feel.
Well, I've noticed that a few things have great impact on the DPS you can get on a dungeon, mainly: DG level, affixes and how your tank does his job.
Let me explain a little better:
1) DG Level - the higher the level, the longer takes the adds to die, so the DPS relevance of your bursts / mini bursts is worsen, since you spend most of the trash fight just casting stuff. If you can burst & kill a pac of 4 - 5 trash in 10 sec or less, your DPS will be much higher
2) Affixes - some affixes, such as Volcanic (now, without Icy Floes!) can really screw up your DPS, so when you check your DPS against other players, this is something to keep in mind
3) Tanking - some tanks just grab 2 - 3 trash mobs and wait for the group to kill them off, instead of aggroing a larger group. Other tanks like to aggro the entire room. The second case will net you a much higher DPS (such as the rat pack in Arcway), and this can make a huge difference. Just to give you an example, in the beginning of Neltharion's Lair, before you jump down to first boss, I've gotten as high as 1.2 MM DPS on that trash, and as little as 350k DPS. It pretty much all depended on how the tank aggroed the mobs.
To give you a numeric reference: I'm sitting at 886 ilvl, with shitty-ass legendaries that do nothing for my DPS, and I pull around 350k - 400k on single-target fights with my Mythic+ build (Conf - Shim - RoP - AF - Fren - LB - Cinder). My stats are something like: 54% crit, 9% haste, 14% mast and 5% vers.
