I'm too lazy to undertake this analysis, but I hope somebody else will. The last Dáil was the first where those elected automatically vacated any local authority seat they had.The idea was to raise the standard fo performace of our "depities". Does the outcome of this election tell us anything about the effectiveness of the end of the dual mandate?
For example, Denis O'Donovan lost his seat, and had tried to take on a role as a national parliamentarian, chairing an Oireachtas Committee or subcommittee on same-sex marriage. Somehow, I doubt it was his middle-of-the-road views on this that lost him many votes in Cork South West.
On the other hand, my local FF deputy, John Curran, has also served on a nationally news-worthy Oireachtas committee: the ad hoc one established to deal with the fallout of the High and Supreme Court rulings on statutory rape and the age of consent. In his literature, the only national references I have seen are his reproductions of FF press releases on pension rates and some stuff on how to apply for other benefits. Most of his monthly newsletter is taken up with stuff he has no say in as a member of the nation's parliament (including one wonderful piece claiming credit for the location of a bus stop in Bawnogue).