I will copy my post from PO forum where i reply a comparision bewteen new Kyurem's forms with Palkia, saying that the new forms should be compared with Rayquaza:
Well, Palkia is probably better in its niches than the new Kyurem's forms, but i don't think the new forms should be compared with Palkia, but with Rayquaza in terms of wallbreaking, look their advantadges over each other (i won't talk about all they can do since they're similar in somethings, i will talk just about the differences):
Rayquaza
-Priority move
-Spikes and Toxic Spikes Immunity
-Powerful STAB Dragons attacks (both physically and specially) and Coverage through Fire and Fighting or Ground attacks
Kyurem
-Bulkier
-STABed Ice attacks to take down Groudon and Lugia easier than MixQuaza
-VERY powerful STAB Dragon attacks, and Coverage through Eletric or Fire
Let's imagine these walls (some are physical, some special, some are both):
Groudon, Lugia, Giratina, Blissey/Chansey, Skarmory, Ho-Oh, Tentacruel, Ferrothorn and Forretress
Rayquaza with Draco Meteor/ExtremeSpeed/Outrage/Overheat can hit all of them for super effective damage, except for Groudon and Lugia that could do something while surviving. Rayquaza can't SE damage Chansey, Ho-Oh and Tentacruel either, but Outrage kills those anyway, the problem is that it gets locked into Outrage and can be trapped by Ferrothorn, so Brick Break is an option over Outrage to still kill Chansey, but in this case it loses the power of Outrage to quickly kill Ho-Oh and Tentacruel, so let's says that Rayquaza puts V-Create over both Outrage and Overheat, what means it still has the Fire coverage and now can kill Chansey like it had Outrage, it opens door for one last slot that can be fullfiled by Earthquake to kill Tentacruel quickly without get locked, or Outrage to kill quickly both Ho-Oh and Tentacruel while getting yourself locked.
When i say "to quickly kill someone" i mean a way you can remove a threat from the opponent's team without receive to much damage (for example, a MixQuaza without Outrage would not kill Ho-Oh with Draco Meteor, ExtremeSpeed, or other attacks, and would be seriously damaged by Brave Bird).
Well, even if you aren't affraid of being locked into Outrage, then you get Draco Meteor/ExtremeSpeed/Outrage/V-Create, but you have not Brick Break or Earthquake to quickly kill Heatran and Dialga.
And after all of these you still won't kill Groudon and Lugia in one hit.
Now let's see Kyurem:
The same walls i put against Rayquaza are destroyed by the same coverage, but now i can ignore Sturdy from Forretress and Skarmory killing them in one hit with Fusion Flare or Fusion Bolt (depending what Kyurem i'm using), ignore Flash Fire from Heatran seriously damaging it with Sun-Boosted Fusion Flare, or even trying Focus Blast against both Heatran and Dialga. Now i have a much easier time against Groudon and Lugia than MixQuaza unleashing my STABed Ice attacks, or killing Ho-Oh and Tentacruel with Fusion Bolt to don't get locked into Outrage.
I just see only two real problems when comparing Mixed Movesets from the new Kyurem's forms with MixQuaza:
1-The absence of a powerful physical attack that don't get you locked (Outrage) or that doesn't have to charge (Freeze Shock), meaning that Kyurems will have a harder time to kill Chansey than Brick Break/V-Create Quaza;
2-You will have to choose between Fire and Electric. Chansey, Ho-Oh and Tentacruel can hold against the Fire one unless it Outrages them, but saying again, getting locked is a problem bigger than SR weakness. Chansey, Ferrothorn and Forretress can stand against the Electric one, unless it Outrages or Freeze Shocks Chansey and has HP Fire.
Personally i would go Focus Blast/Freeze Shock/Fusion Bolt/HP Fire with Black Kyurem, because Freeze Shock cause massive damage against Groudon and Lugia, and the only two Dragons that don't get SE damage from it are Palkia and Dialga. Palkia get killed by one hit anyway (it's not like someone would switch a Palkia into this attack, or i would switch Kyurem against Palkia, but i'm just exploring its potencial), and Dialga (and Heatran, and Tyranitar) get killed by Focus Blast. HP Fire for Ferro and Forry, Fusion Bolt for Skarmory, Tentacruel and Ho-Oh (i could kill the phoenix with Freeze Shock, but i don't want to charge). Freeze Shock kills Chansey easily too if she don't have Protect.
And with White Kyurem i would go Draco Meteor/Fusion Flare/Ice Beam/Outrage.
Actually i think Black Kyurem is BETTER than the White one, despite all the people saying the other way, because HP Electric is a bad idea, but HP Fire isn't, so the Black can have Fusion Bolt and HP Fire, but the White can't have Fusion Flare and HP Electric (unless you don't know what you're doing, because HP Electric is not worth it), giving the Black a better coverage. The OTHER reason i think that is because the Uber Metagame is Specially oriented, so generally peoples expend more EVs in Special Defense for theirs walls, resisting better against the White one, but being more vulnerable to the Black one.