I'm from Portlaoise and rent out a section 23 property for €700 p.m. It's the first letting and it took only a week to rent the apartment. I spoke to the three local letting agencies who all told me there's a glut of 3 and 4 bed houses in the town, but that 1 and 2 beds are in short supply. I wouldn't be in a hurry to invest in a 3/4 bed house in the town becuase there does seem to be a lot of them about. The letting agent I use is
http://www.propertyproperly.com/ I'd call all the local agents (listed in local paper the Leinster Express) and ask their advise. They know what tenants are willing to pay and what's on the market.