Well, since the Emirates flights both ways are daytime flights you probably won't be sleeping, so the bed configuration probably doesn't matter too much. If you do want to sleep, then Etihad has a better seat.

Etihad also has more flights with better timings: the Emirates flight leaves Dubai at the crack of dawn (you'll be up at 4am) and gets back to Dubai after midnight (you won't be at your destination until at least 2am).

Both airlines have chauffeur drive at both ends so they are roughly the same on that front.

One real difference is the Dublin lounge: Emirates use the DAA lounge which is as basic as lounges get. Etihad have their own lounge which is much nicer.