Originally posted by xPRIMExIt is possible that Palpatine's initial clone vessel may have still contained the entirety of his power -- hence Kylo's comment upon first encountering him:
Seems to me that the clone body was deteriorating because it was not able to contain his immense power. So although he may have been physically weaker, that doesn’t mean he was less powerful at all.
But the Force itself belied any perception of frailty because a cloud of darkness and need swelled from the creature, along with power like Kylo had never before encountered. It was exhilarating.(Which scales pre-dyad Palpatine above the likes of Snoke and Luke.)-RoS novelization
However, his vessel was an imperfect/errored replica of the original, and therefore could not sustain the immense power that Palpatine wielded without continuous life support via the Ommin Harness:
The figure moved closer. He was unspeakably frail, his body dangling from an enormous mechanism that disappeared into the darkness above. Kylo had seen this before, while studying the Sith, and again while researching clues about Vader's wayfinder. It was an Ommin harness, a mechanical spine once worn by an ancient Sith king. Without it, the emperor could not survive.-RoS novelization
That's why Palpatine wanted to transfer his essence into Rey. Her body was, essentially, a perfect vessel that was capable of housing his essence:
The heretics of the Sith Eternal toiled, splicing genes, bolstering tissue, creating unnatural abominations in the hope that one of these strandcasts would succeed and become a worthy receptacle. The heretics would do anything, risk anything, sacrifice anything, to create a cradle for their god-consciousness.
Nothing worked. But their efforts were not entirely in vain. One genetic strandcast lived. Thrived, even. A not-quite-identical clone. His "son." But he was a useless, powerless failure. Palpatine could not even bear to look upon such disappointing ordinariness. The boy's only worth would lay in continuing the bloodline through more natural methods.
And it was through that eventual union, unexpected as it was, that Rey was born. The perfect vessel. Strong enough to contain all the power of the Sith. His granddaughter...-RoS novelization
But when Palpatine absorbed the dyad juice from Rey and Ben, his body was rejuvenated, and subsequently transformed into a suitable vessel(which made Rey irrelevant):
Sidious at first plans to take over Rey's body as a receptacle strong enough to hold his spirit, but is surprised to discover that Kylo and Rey are a dyad in the Force of great strength. By drawing upon their power, he can revivify his body.-The Star Wars Book
That said, while pre-dyad Palpatine may have still housed the sum total of his power, I do not believe that he was capable of tapping-into/utilizing said power to its full capacity(likely because it would speed up the deterioration process), as Rey indicated that post-dyad Palpatine was even stronger than he had previously been:
Rey and Ben lay collapsed on the floor as Emperor Palpatine released himself from the Ommin harness and drifted down. He stood straight and strong now. Invincible.[...]
He raised his hands as though reaching toward the battle overhead. Even through her haze of weakness and exhaustion, Rey could sense him draw on the Force. The Emperor's power was staggering now.
-RoS novelization
So it would seem that post-dyad Palpatine > pre-dyad Palpatine for two major reasons:
a.) He could indeed tap into the full breadth of his powers without suffering any undesirable side-effects to his physical body.
b.) He was fully independent, and no longer reliant on dark side tech to survive.
Originally posted by Scizard
It's clearly to Palpatine. Why would it be an unspecificed Sith Lord, they don't all have equal strength it makes no sense for him to be equally as impressive to them.
But why mention Sith Lord at all? Putting that title in does leave at least a small amount of ambiguity.
But then a lot of source book quotes do that.
Which is just another reason one off source books quotes cant define canon on their own IMO.
Having said that, now that we know Snoke was a clone of Palpatine, that may give more reason to believe he could have been his equal (to an extent). Clearly he was never his equal in the same time period though.