Okay, so I'm not following all this discussions, but there are a view things which disturbs me.
OS Erza isn't even close to OS Jura. I don't understand why some people think this. Jura showed way more impressive feats in this arc than Erza did. Jura took down Brain, who is the leader from the Oración Seis, with easy diff. Erza took down Midnight with high diff. So if OS Erza is stronger than OS Jura, this means Midnight is tiers above Brain. No, just no. Even though I think Midnight could be the strongest mage from Oración Seis, he is still more or less equal with Brain. They're on the same tier. Jura had way less trouble with defeating an Oración Seis tier mage. Isn't this already proof that OS Jura > OS Erza mid diff, based on 'calculations'.
There isn't a big difference between Second Origin and 7 years of training. Yes, Erza showed us how strong she was by defeating 100 monsters in Pandemonium, but would she had the same score as Jura with the MPF? Nope. Jura has more magic power than Erza. Jura has feats above Erza like strength, power and defense. Erza would only outclass him with speed. And remember what Jura did against Jellal's Meteor? Erza has a nice stamina, but she can't keep up with Jura's defense. GMG Jura > GMG Erza.
And now we're in the Alvarez Arc. Erza became stronger but so did Jura. But exactly what made Erza look a lot stronger than GMG Erza? Her strongest armor is still Nakagami Armor. What did Nakagami Armor showed us so far? Well, she took Minerva down with it which is quite impressive, but she didn't defeat Ajeel with it. She just gave the final blow which wasn't needed. Erza was overpowered by Ajeel. Even if she would've used Nakagami Armor before the Jupiter blast, she still would've been overpowered. Both Erza and Jura aren't Spriggan tier. Both of them haven't shown a lot of new feats compared to the GMG arc. I'd say Alvarez Jura > Alvarez Erza because Erza can't surpass Jura if he has trained as well.
In the end, Jura > Erza high diff. And I think it would be high diff because Erza gave a good fight against Ajeel.