Sulla didn't really want to "fix" anything, at least not in the sense that he hoped by constitutional reform to construct a stable, self-sustaining government in which elements of thr state would be able to work together harmoniously according to their appointed roles. As Shackleton Bailey said, although lots of people saw that there was something wrong with the state, until Octavian pretty much nobody put any thought to a realistic way to resolve the problem, with the possible exception of Caesar towards the end of his career (and there I disagree with Bailey--I would argue that Caesar didn't do what he did--particularly his deliberations on the kingship, which is what Bailey means--because he thought it might fix the state, he did it because he wanted to be number one). Cicero's idea of the concordia ordinum isn't really a solution, it's the statement of an ideal--Cicero didn't identify a solution, he put into words the way the legal system as it already existed should work. Cicero considered Sulla to have undermined it just as much, if not more, than Marius--Sulla's laws were very hotly opposed by Cicero, even if he was willing to defend the letter of the law in his duty to stability. Sulla's laws were extremely divisive, and were intended as such--the purpose of the Sullan Constitution was not to reform the state into one that was stable, but to hamstring his political opponents and prevent another Marian faction from rising. They granted enormous power to a very small group of men, thr nobiles, those with a consular ancestor. Even members of the senatorial class without consular lineage were heavily targeted by his laws--the doubling of the size of the senate was intended to prevent any individual senator from holding too much influence, but at the same time intentionally reinforced the power of the small group of nobiles, whose auctoritas was largely unaffected. By refusing to allow the equites to serve on juries Sulla prevented the possibility of anyone but the nobiles making judicial decisions, as almost all patricians had consular ancestors. And the hamstring of the tribunes was certainly not intended as a stabilizing measure, it was done out of spite and fear. Marius had gained great influence as tribune, and had flouted the will of the senate several times during his tribunate. Sulla removed all power from the tribunes, rendering those outside the senatorial class voiceless--since the sex suffragia held so much influence in the assemblies without tribunate assistance Sulla also intentionally prevented anyone who wasn't a high-ranked senator from even voting. And many of his laws he surely knew perfectly well would undermine the stability of the state--his law granting proprietors and proconsuls provincial commands for five years was intended to keep influential promagistrates from returning to the ranks of the senate and spreading their influence, and yet Sulla had gained power by virtue of his actions in the provinces! Sulla's laws were intended to, and accomplished, render everyone who wasn't one of the nobiles impotent--hell, by increasing the number of magistrates at all levels he intentionally made it more difficult for anything to actually get done, since there was a much higher chance that a magistrate would veto his colleagues (thereby preventing individual influence--the nobiles already had influence).

Sulla was regarded throughout Roman history pretty exclusively as a tyrant. Even late sources like Dio or Plutarch resoundingly damn him. His proscriptions were bloody and unfair, and his lack of oversight over the freedmen who carried them out led to extreme corruption--a young Caesar tried to prosecute one of Sulla's freedmen for taking advantage of proscriptions for his own gain, and only barely lost. It's hard to overplay the effect that the proscriptions had on the Roman psyche--they were remembered as a demented, anarchistic time, when neighbors and family members informed on one another and bands of thugs roamed the streets looking for people to lead away and murder. Things like Crassus' corrupt land stealing or Catiline's butchering and mutilation of Gratidianus at Catulus' tomb were encouraged. Marius' massacres had been brief, and had largely consisted of his troops letting loose on their enemies--Sulla's were state-sanctioned, terrifying, and random, since between the corruption and informers by the end of the proscriptions completely innocent people, as well as Sulla's own followers, were being murdered. Sulla's laws were also unanimously considered unfair--Plutarch condemns them resoundingly. Most of the rights he had taken away were centuries old, many dating back to soon after the kingship. His favoring of the nobiles, who made up a tiny portion of the senatorial class, both plebeian senators and patricians, was despised even by many of the optimates, as was his unfair limits on individual ambition, since it left thr state intentionally in the hands of incompetents who had influence purely by lineage alone (Cicero's "fish-fanciers") and prevented anyone not already at the top from rising, no matter how accomplished. Speaking of the optimates, Sulla's legislation was also largely hypocritical--he was the first man to successfully pass land distributions to his soldiers (Marius had devoted his career to getting his distributions, but had failed), despite his refusal to allow anyone else to do it and his professed determination not to allow anyone to distribute the ager publicus, by whose rent many of the nobiles and senators in general were getting rich. It's telling that both sides teamed up under Pompey and Crassus, who had both been Sullans but found themselves in opposite camps after his death, to dismantle his legislation--and they wanted no time on doing so. You'd be hard-pressed to find a favorable report of Sulla anywhere in Roman literature, either Latin or Greek. He was pretty universally despised, and by and large the Romans liked to pretend that the whole episode had never taken place--as late as the In Pisonem, for example, Cicero felt it was an impropriety to openly mention the proscriptions, and had to allude to them indirectly