This depends, the Umayyad did not treat the Christian populations 'well.' There was understanding of one group being submissive, and any rejection of said submission incurred wrath. This is the understanding the Umayyad imposed upon the Christians, one of the strong preying upon the weak; the weak submit for fear of the strong and the strong are possessing of a complex system of protection agreements (Dhimmitude) that regulate relations between Muslims and the conquered peoples.
Islam also played upon the notion that they promoted freedom of discourse for some of the more eccentric Christian sects, such as Arians, Nestorians, Monophysites, Messalians, Paulicians, etc... Italy is a different case entirely, it will be like Iran. A land with a strong and militant population, who has faced war head on for centuries and have a close-kin neighbor in the Franks to the north and possibly the Visigoths to the west. The Umayyads will crack down upon the population and enforce rigidity in order to ensure points for which they can strike upon foes to the north, west and east. This is similar to how they interacted with Iran. Namely, destruction en masse of religious buildings, reprisals for even the most minor riots, slave-taking with deportations and so forth.
In which aspects does Italy differ from Hispania in that regard that make you see such a difference in treatment between the two? Just to understand the ticking point between good treatment and mistreatment, since Hispania became the last refuge of the Umayyad, not their fiercest antagonist