As is often the case in questions like this, the answer is going to depend on one's viewpoint, and what one focuses on. In a more general, broader view, the best answer is probably "both". Castro did a lot of good things for Cuba, particularly when it comes to education, infrastructure, and healthcare. There is no denying that the average Cuban under Castro had a better lot in life than under Batista and his predecessors. On a simple measure like this, the answer would be "Castro did a good job". But then come the caveats. Dissenters to Castro's rule were plentiful, and handled very harshly. There's a reason more than a million Cubans fled his rule. Repression included execution during the early years, but mostly shifted to forced labour camps, Castro obviously taking his cues from his Russian patrons. And herein lies another important caveat to Castro's rule. Many of the advances in quality of life that Cubans experienced were arguably paid for through hefty subsidies from the Soviet Union. There is nothing wrong with that per-say; after all, many former colonial states used the Cold War as a method of gaining investment in the areas that Cuba did. However, without said subsidization, Cuba would not have had the resources to do what it did domestically. On the other hand, without a doubt the embargo by the United States has also had an effect, so the blade cuts both ways.

While everyone in here has been polite to one another, it would be quite another assertion to say that this level of frozen, painful civility is something our community encourages. Our motto is "Be Excellent to one another." This is a contentious topic. While it is important to point out biases in other peoples' work (and we all have them), this should not be in the form of a personal attack. This is therefore a friendly reminder that anyone stooping to a personal attack will find my boot firmly up their backside.

TL:DR Stay polite.