Alright. It's time for me to solo this thread.
Anyone who thinks Edo Itachi actually has a chance against Obito, especially Rinnegan Obito needs to rewatch the series. If this was Obito with the Orange Mask we're talking about here, then we MIGHT have a matchup worth discussing.
Lets begin with AP. The only thing stopping this from being a total shitstomp is Obito not having his Edo Jinjurichi.
Obito pretty much fonoled KCM Naruto, Guy, B, and Kakashi at the same time. He could easily react to all of their attacks with no difficulty. Obito tanked a Rasengan from KCM Naruto with next to no damage. The only way any of them were able to damage Obito at all was thanks to Kakashi having Obito's other eye.
Next, I'm going to dismantle Itachi beating Nagato as an argument.
Now Itachi briefly traded blows with a fatigued KCM Naruto who before created like thousands of clones, and sent them across the planet. He wasn't stomping KCM Naruto and B at the same time. Nagato fondoled both of them with 0 difficulty, and nearly killed them both. Itachi couldn't dominate Naruto and B to the same extent.
Itachi didn't beat Nagato conventionally. He outhaxxed him. And Nagato wasn't even in control of his body at the time iirc. Quite frankly, Itachi would've been ****** against Nagato were it not for the Toutska blade. Let alone his Chibaku Tensei.
So no. Edo Itachi is at best somewhat relative to Nagato. But certainly not above him.
Now for Speed.
Obito eclipses pretty handily here. He could react to attacks coming towards him from behind. He could react to KCM Naruto without trouble, along with B, War Arc Kakashi, and Guy.
Itachi was trading blows with a fatigued KCM Naruto, who wasn't at full power.
So Obito is comftorably above Itachi in speed.
Abilities.
Amaterasu gets dodged with ease. Even if it does hit Obito, he can absorb it with the PReta Path, or push it off himself with Shinra Tensei.
Tsyukiyomi. Obito knows about Itachi's Genjutsu, and his Rinnegan would probably neg it anyways.
Susanoo. The Yata Mirror isn't going to block Kamui, and unless someone can prove to me that the Toutska Blade can hit intangible beings, that aint going to hit Obito either.
Lets not forget, Obito CAN use all of the Rinnegan's abilities. And frankly I don't buy the whole idea of it "being too taxing for him" This dude could casually control the Gedo Mazou, whitch originally screwed up Nagato's body. He controlled 6 Biju without effort. And later went on to have a huge portion of his chest destroyed, the Ten Tails extracted, and being forced to cast Rinne Tensei.
What I'm saying is that there's no reason Obito cannot use the Rinnegan's powers freely.
Now lets discuss win conditions.
Obito: Can seal Itachi vs Chibaku Tensei, Can BFR Itachi into Kamui, Can pull out his soul with the Human Path.
Itachi: Could seal Obito with the Toutska blade if he gets lucky.
Conclusion: Obito outmuscles, outspeeds, and outhaxes Itachi in this fight.
Normally I'd call something like this a stomp, but because of the Toutska Blade, and my favorable opinion of Itachi. I'm gonna throw him a bone and say he might win 1/10 battles. With Obito winning 9/10 handily.