It's the same story on the London routes. Aer Lingus and Ryanair are way too cosy on those routes, and there's very little difference, if any, in fares
If you are just talking about the fare with no baggage or other addons then I would have to disagree entirely if you're a reasonably regular traveller. Depending, of course, on how long you book in advance EI's fares London-Dublin are way in excess of FR. An added and important factor is the admin fee. Using the FR Cash Passport you don't have to pay the extra £12. Before that you could use one of the easily bought Mastercard Cash cards. EI only offers the unobtainable Visa Electron as an alternative so you can add £12 onto the fare for every return flight. How they have managed to get away with that for so long I don't know.