I'm also in that development, and have no problem with cinergi. PM me if you want the number of the local rep. He was helpful.
you can stay with Eircom and just get cinergi broadband, or move the whole lot to cinergi (which is what i did).
I use it for working from home, so the 5GB limit for 14.99 is great value, and i've never surpassed it (not one for downloading movies and whatever)
I changed the home phone to cinergi because the charges were about 10-30% cheaper, but the monthly rent wasn't any cheaper, about €24 p.m. I never use it, but my wife does