The answer to this question will come down to each person's individual preference for the functionality of a sci-fi super weapon. If one considers the sheer might of the Starkiller Base and nothing else, then it is clear that the Starkiller Base is the better of the two.
Introduced in Star Wars Episode VII: The Force Awakens, Starkiller Base was born from the remains of the planet Illum, where Jedi would go to find their Kyber Crystals. With a huge battery to focus its power, the massive base could wipe out entire systems with better efficiency than the Death Star.
The second Death Star is substantially more advanced and more powerful than its predecessor, and the critical weakness found in the first Death Star has been removed—the Rebel Alliance's only hope is to destroy it prior to its completion.
The Death Star is a planet killer. Starkiller Base is basically a planet turned into a machine. Also seems like the Death Star would have the advantage here. Death Star only needs minimal time to charge up while Starkiller Base needs the time it takes to suck up a whole sun.
How big is Starkiller Base compared to Death Star?
The surface area of Starkiller Base, using Wookieepedia's diameter measurement, is about 528,102 square miles. The first Death Star's surface area would be about 30,791 square miles; Death Star II would be 48,305 square miles.
He is pretty powerful, definitely up at an A tier level of ability. He has faced quite a few potent Jedi masters. If memory serves, the most powerful person he beat outright was Shaak Ti. He did technically beat Vader, but he used lightning and then damaged his suit with a hurled piece of debris that exploded.
Starkiller Base drew its power from the energy of stars, a possible reason for its name. As Starkiller Base finalized its construction, the First Order moved towards its campaign for galactic power.
Lord Starkiller is an antagonist in an alternate Star Wars timeline in which Darth Vader is defeated and killed by his former apprentice Galen Marek, code named Starkiller.
Kylo defeated Finn and disarmed him. But Rey took up Skywalker's saber. Rejecting Kylo's invitation to show her the ways of the Force, she attacked him – and Kylo found he was no match for her power and rage. Rey defeated him, and Kylo escaped Starkiller Base before its destruction.
Subject 1138, known informally as "Starkiller," was a clone created as a result of the death of his template, Galen Marek, the original Starkiller who died while saving the leaders of the Alliance to Restore the Republic.
The Death Star's most famous weakness was its thermal exhaust port, but Star Wars has hinted the battle-station had another critical weakness that would have become clear over years. Emperor Palpatine intended the Death Star to be almost invincible, but he had not factored in Galen Erso's sabotage.
Who is the most powerful person in Star Wars history?
In terms of pure Force powers, nobody in the Star Wars canon comes close to matching Master Yoda. Living long enough to teach many generations of Jedi masters, Yoda was the leader of the Jedi Order for centuries before its fall.
Out of the 2 billion inhabitants on Alderaan - with the modern-day populations of China and India having about 2.8 billion people combined - about 60,000 survived the destruction of the planet due to being outside of its star system at the time.
During the match, Luke remarks that Starkiller was making him angry, and when Luke is then defeated by Starkiller, who mocks him on destroying him as he "destroyed his father", Luke screams in anger and falls to the the dark side as Fallen Luke.
However, Starkiller still managed to best Kenobi - defeating him in combat and causing his spirit to disappear with a blast of Force Lightning. Unable to battle Starkiller, Kenobi's spirit told Luke to run, with the Millennium Falcon fleeing Mos Eisley.
Why does Starkiller hold his lightsabers backwards?
The inverted grip, which results in the lightsaber being held behind the back, was specifically used to perform sweeping attacks, but many Jedi would argue that the user leaving their front exposed is contrary to the defensive aims of the Shien variant and Form V.
JJ Abrams told Empire in August 2015, "Kylo Ren is not a Sith. He works under Supreme Leader Snoke, who is a powerful figure on the dark side of the Force." Abrams had previously stated that the character "came to the name Kylo Ren when he joined a group called the Knights of Ren."
It is also outright stated that Sidious was feigning weakness to goad Starkiller into striking him down and to turn him to the Dark Side. He didn't beat Sidious. He even went oneness and then died to Sidious.
He displayed incredible control of the Force, from moving a Star Destroyer to defeating both Vader and Palpatine in succession. Galen Marek seemed to be not only one of the strongest Sith Lords, but one of the most powerful Force-users in all of Star Wars.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker. Galen was secretly trained as a Sith Lord apprentice to Vader, but returned to the light side and the Jedi.
As we seen at the beginning of the game, Vader had undergone a rigorous gauntlet of trying to find the perfect Starkiller clone. Likely giving each a set of lightsabers.
Both bases could take each other out, but the Death Star might actually be the better of the two thanks to its higher functionality and more reliable fuel source in relation to the power it requires.
