The difference between the Sannin and all these new OP characters is that they were all naturally talented, with no special bloodline or anything. They all have/had their own unique abilities and could still go up against all the current Kages, and as a threesome against Madara (not saying they'll win)
Orochimaru is by far one of the most powerful well rounded ninja displayed in naruto, but was ahead of his time, thus the reason why Kish had to kill him off and kept him at a weaken state. He had great defense, offense, genjutsu, sealing and summons which made him a force that many ppl feared just by his name. I can't think of many characters who could have turned another against the leaf and establish their own in such lil time, without controlling them. Also, his intelligence factor can't be ignored, thus being knowledgable in numerous jutsu, experiements and figuring out Tobi/Madara plan. This dude simply was the shyt, but had to have a weakiness, which was the Uchiha. Also, I just wanna state the whole itachi owning with genjutsu is false, as I watched the clip Oro smiled and ws about to release it but itachi prevented it by cutting his hand, it's that simple.
Jman is the from master and is very powerful too. Though he might not wield a range of jutsu, what was great with what he was capable of doing. He had good endurance, strength and analysis all without Sage mode. Also, Jman was in a harder situation than Naruto when facing Nagato (who wasn't even trying to kill him). Jman simplying went in there not knowing anything and was caught off guard throughout the whole fight, yet he still held his own against a "God."
Tsunade may not have shown much, but the chick is powerful and I'm sure she is something to watch in the battlefield. She's known for medical abilities, which she influenced the whole movement of such abilities in a group. That's all I can really say about her.
Let's take into consideration that the Sannin were much older when we got a chance to see them in action. After fighting Hanzo they all grew into great ninja without all that fancy shyt.