Note: This is based on NZ

Legislation, so references to law may not apply or may differ in other countries. This is NOT a legal opinion
NZPC has lots of experience with rental properties - both by owning them ourselves and also with clients. We've managed the ones we owned also contracted out the management
There are three ways to manage a rental property:
Self Managing
You do all the work!
This is good if you
have lots of time and are willing to invest it in the marketing of the property, screening of tenants and then ongoing inspections - NZ Insurers state that inspections must be carried out quarterly
Problems:
No access to the lists of prospective renters that Property Managers have
Ensuring compliance with ongoing developments in legislatio
Managing via Estate Agent's Property Management Arm
This is our preferred option:
For:
Real Estate Agents in NZ are regulated by law (REI Act); Property Managers are NOT!!
The property will be marketed on the Agency's main website, so lots of people viewing it
Agency will have determined processes for effectively screening tenants
Agency will have processes to ensure that they are conversant with law changes.
Agency will have access to proven maintenance people
They have access to market data, so will price the rental accordingly: we recommend asking for the 60th - 75th percentile price if the property is in excellent condition: you want a good price but one that ensures that the property is rented to one tenant for a long term!
Against
You will have to pay a fee : In Auckland this can be 6-8% of the rent, plus the same fee for maintenance. Ideally, you won't be charged an inspection fee. The fees are negotiable, but don't trade price for quality