I too have just come back on this route (both ways) Im afraid I was not as enamoured of the Aer Lingus experience as the OP.
My route was LHR-DUB-MCO and back.
We have travelled DUB to PHL and ORD with American and I have to say, their service I found to be much better.#
Outbound.
Picked up both legs tickets at LHR, that bit of the process was easy.
Then however, we were stuck on the tarmac at LHR for three hours, as Dublins Radar had broken.
Some people got off as their trip was not worth it any more.
Finally got to DUB and Im a wheel cahier user for long walking distances. Dublin brought a wheel chair to the gate but then expected my 16 YO son to push me to Terminal 2, and the route for wheelchairs was closed off once we got far down it. Not Aer Lingus fault, rather Dublin Airport.
Security seemed to take longer than normal and grumpy Irish customs officer, USCBP didn't show us our cases and again, was longer than normal.
The bad side of Aeer Lingus is that it does not participate in TSA Pre, which is a valuable thing especially on the way back.
51st and Green does look a lot more shabby than last time we were here (2 years ago after it just opened) still its OK.
Onto the plane and I had seat 3k (captains chair) Plenty of room, but over the flight I found the seat rather uncomfortable and the massage facility, whilst a good USP, was terrible.
Food was OK, but (shock, Horror!) Vie had better food on even BA.
Flight arrived 45 min early
Greast, but then we had to stand around for two hours waiting for our third bag to come off baggage claim, it didn't, Midnight Florida, shattered and having to fill in a baggage lost claim.
Bag finally turned up 4 days later.
Returned flight.
As said before, without TSA Pre, you have to join the massive queue going through security, this took 2 hours, negated th bonus of outward flight.
No Aer lings lounge, but like BA used the same lounge, which was better than 51st and green.
Same seats on way back.
Food, normal for USA to Europe flights, pretty poor.
Now, the seat/Bed. This was my main gripe, same as my wuifes.
You get one soft pillow and a blanket.
You cannot get comfortable in bed mode with this too soft pillow. I ended up putting the blanket under it to get some height, the wife tried raising the back of the seat a bit.
Then, the coffin for your feet. Sorry, if you lie flat on your back its OK, but still too low at the head and the seat gives you backache, but if you lie on your side, you cant get comfortable as there is no room to bend your legs. Never had this issue on BA, AA, Delta and many other airlines.
Meant all three of us had poor sleeps and arrived into Dublin very grumpy and my son was feeling sick, again never before has he felt that way.
Would I fly Aer Lingus again? possibly if the price was good, but I would always fly BA, American or many other airlines first if price was comparable.