Using GPS in Ireland.

We went to visit friends in lombardstown (near Mallow) yesterday and took a different route home. I had the GPS up (Navman ICN510 - Teleatlas maps) and it showed me quite clearly how bad the maps are. For a lot of the journey we were off the main road and the GPS showed a blank. I wasn't familair with where we were and we eventually got near the main Cork-Mallow road. There it was on the screen all tantalising in its green primary roadness. But no sign of how to get onto it. We eventually made it but no thanks to the GPS or indeed Irish signposting which directed us to take a left for the N20 and then a few hundred yards later was a fairly large crossroads without any signage...pah... I wonder are the new Navteq maps any better ?