Landlord Warranty of Habitability

Landlords are required to keep residential premises in a state fit for human occupancy pursuant to the warranty of habitability; however there are plenty of stories about cockroach or rat infestations affecting apartment buildings. Do you think that most tenants are aware of the warranty of habitability, that is to say, do you think they know they could require a landlord to address unsanitary conditions? How do you think landlords should be held accountable to ensure that all premises are fit for human occupancy? How prevalent do you think landlords violate the warranty of habitability? Do you think the standard of what is considered acceptable conditions varies from location to location, (city, state)? If the goal is to ensure that all apartments are fit for human occupancy, should the location of an apartment impact the acceptable standard of sanitation? This is an open forum, feel free to share your ideas freely.