Does it matter if I rent directly from a landlord or through an estate agent? 

In Ireland the tenant does not incur any additional costs by viewing properties that are being marketed through agents. The agent’s fees and costs are paid for by the landlord that owns the property. No agent should charge you a fee for viewing a property or indeed for carrying out reference checks.

Many agents are members of professional bodies such as the Institute of Professional Auctioneers and Valuers (IPAV) or The Society of Chartered Surveyors Ireland (SCSI)