After defeating Astyages, Cyrus took him on as an advisor in his court, treating him well.
When Astyages sent an army to fight Cyrus, they deserted him in favour of Cyrus, suggesting that Cyrus might treat his people better than Astyages
After defeating Croesus, Cyrus was going to burn him on a pyre, but at the last moment decided to save him and also kept him as an advisor.
When Croesus was let off his pyre, he looked at Cyrus's soldiers who were looting the city and asked Cyrus what they were doing, Cyrus replied that they were ravaging Croesus's city, to which Croesus said that it was Cyrus's city now, this may suggest that Cyrus may not have treated the people he conquered that well when he had just conquered them.
Once Cyrus had conquered Lydia, the Ionian Greeks asked to be subjects of Cyrus under the same terms that they had under Croesus, but Cyrus refused them, so the Ionian Greeks resulted, but were beaten and forced to submit to Cyrus's terms through fear. This suggests that Cyrus's treatment may not have been as good as it seemed
After Conquering Babylon, Cyrus captured of Nabonidus, the former ruler, possibly not treating him that well, but the people were apparently being oppressed by Nabonidus, so Cyrus may have freed the people from a tyrannical rule.