Whenever discussing "pros" and "cons," it is important to remember that what was good for one person, or group of people, might not be good for others. So assessing "pros" and "cons" is really a matter of perspective. One pro for the Romans was that Caesar was an immensely talented military leader and general whose victories substantially enlarged and expanded the Roman Empire. He won a massive series of victories that solidified Roman control over Gaul, led legions successfully into Britain, and defeated enemies from Asia. It was these military successes, in fact, that paved the way for his political career.
As a leader of Rome, Caesar's legacy is complex. For most of his life, Rome had teetered on the brink of civil war, and he ruthlessly exploited this instability to his own gain, naming himself dictator-for-life after defeating the armies of his ally-turned-rival Pompey. As dictator, he instituted reforms that generally increased his popularity with the Roman rank and file, enacting laws that were lenient toward debtors and providing work for landless poor people. He also took steps toward reforming the corrupt nature of Roman provincial government, though he accomplished most of these changes by placing friends in the Senate and other places. He also appealed to the people by staging elaborate spectacles at the public expense. Ultimately, Caesar's actions set in motion a chain of events that would lead to the collapse of the Republic and the beginning of the Empire under the rule of his nephew and adopted son, Octavian (Augustus). However one weighs the "pros" and "cons," Caesar's life was enormously important in reshaping the Roman Empire. But for many Roman aristocrats, Gallic people, and of course his political rivals, his rule was an unmitigated disaster.
This is a good question and many things can be stated.
Here are some positive things Caesar did. Caesar was known for his clemency. So, when he fought against Pompey, he did not kill everyone who went against him. In fact, he pardoned them. So, he was a person who stemmed further bloodshed. Caesar was also very tolerant when it came to religion. For example, he granted freedom to the Jews in Rome.
As for negative points, Caesar was a man of war. He was not able to "fix" Rome from incessant war. Under his watch, he fought other Romans and his ambition got him killed.