Tbh they feel same same to me, Super Broly is literally still just a big screaming powerful toddler and I do not understand why fans try to discredit the old broly when both Broly's are big babies in a different way. Old Broly was born a super powerful being and was cast aside by his race for his insane power level. Instead of holding a grudge against the people who tried to kill him and tossed him aside, he goes around destroying galaxies with a vengeful grudge against a random crying baby. Somehow over 30 years he still remembers the name and exact features of this baby and blows up in a ridiculous rage when he spots said older baby. The plot is pretty fucking ridiculous, but the movie not only pre establishes that Broly is insanely powerful, he does a little more than scream kakarott, and is just gruesome, evil, and brutal person. Old Broly was like the embodiement of pure chaos and only existed to create destruction. He was the embodiement of everything ruthless saiyans represented, he was the original legendary saiyan, he would probably be revered as a god by the saiyan people. He has no emotional attachments he's just a cold blooded machine.

Now on the topic of Super Broly, much like the old movie, Broly was a child born with unimaginable potential, and king vegeta sent him off to an uninhabited planet. Super Broly, is then joined on the planet by his father and is raised on this planet for 40 years until one day some frieza soldiers stumble upon the pair. Frieza recruits the pair and Broly, while powerful, is in an infantile state as a man in his mid 40s. It makes sense that Broly is left in a childlike state after 40 years of no socialization or contact with another lifeform outside of his father. To hold his power back, his father places and electric bracelet around his neck to limit his power. Then goku and vegeta get a whiff of frieza's presence on earth and go to approach him. Then Frieza proceeds to sic Broly on the saiyan pair and all Broly proceeds to do for the next 40 minutes of screentime is scream and power up from a level around ssj1 to a ridiculous amount above god form and proceeds to stomp out goku, vegeta, and frieza with the power of screaming. He reaches a level beyond goku and vegeta's god forms in about 10-20 minutes of screentime through excess screaming. Hell even in the games all super broly does is yell and grunt in every attack. You see what im getting at? I see the potential Super Broly has to become a better character, but to be honest Super Broly isnt that big of an improvement from the original Z broly in my opinion. Like I understand what they were going for with that take on super broly, but I dont understand why he's revered as some godsend of a character.