Well the poster only asked for opinions on Lucan.They did not ask for alternatives.
However in the area, as others have said Maynooth is better. Indeed given its close proximity to Liffey Valley maybe Ballyfermot is a better choice.
Personally I would recommend going as close to town as their budget allowed. As the market is falling at present I may not buy atall but rent for a while and decide themselves after a while living in Dublin.
Nodser, I'm living in Lucan the last 12 years, originally from Ballyfermot and currently rent property in Ballyfermot. Although Ballyfermot has some great people living there, I wouldn't like to bring up my children there. Similarly for Inchicore, Rialto etc. The closer you get to town, the less safe it is and harder for children to play outside etc.
You mention Maynooth, well Carlow is a fantastic town, and so is Kilkenny, but I think the OP was looking for a house in West Dublin, if not Lucan.