I have mixed feelings. Going from JFK to Europe (which is the route my husband and I take several times a year), we have several options:

BA F:

Pluses:

Excellent check-in, good people, positive attitude, quick going through security. Really makes you feel special from the word go.

The CCR is quite nice. Not as nice as a restaurant in Manhattan (I don't care what people say, it just isn't). However, given traffic patterns and all that, it makes sense to get to JFK early and then relax and have a nice enough meal at the CCR. The service there is lovely, btw.

Spa services are, not exactly world-class, but as good as you are going to find at an airport. And I like having a massage or a facial and getting all my make-up off and a nice moisturizing treatment just before getting on an airplane.

CC can be hit or miss, apparently, but my experience has been that they are extraordinarily nice. Of course, I am low-maintenance.

Seats are comfortable in every position, and don't require a lot of work to turn them into bed mode (though CC come over with the duvet etc. and quickly convert them into a bed with little fuss).

Good breakfast.

A million times better than CW. It's not that F is a superb product. It's that CW is . . . CW.

Minuses

Dinner on board is not fantastic. The light consommé was good.

Can get terribly loud. Not entirely sure why.

For a small cabin, it feels crowded.

Flying through LHR has its own cons. It is what it is (sorry for the Americanism).

AA F (77W)

Pros:

Amazing hard product. Pretty much perfection. YMMV, of course.

Pre-selection of meals ensures that you get to eat what you prefer (unless something goes terribly wrong).

CC is usually quite warm and friendly, in the manner of AA, especially if you have status (this may not appeal to everyone).

The cabin itself is quite comfortable, and feels uncrowded, without the need for suites (if you like the privacy of suites, neither BA nor AA are the airline for you).

Lots of "comfort food" available to snack on (the spousal unit was quite fond of the banana pudding -- me, I don't snack).

Remarkably quiet cabin.

Cons:

The food is still AA food. 'Nuff said.

The Flounge is no CCR, by any stretch of the imagination. The food there left much to be desired. Indeed, we found that we much preferred the warmth of the staff at the JFK AC, perhaps because they know us so well and are so kind to us. The FLounge staff at LHR, while perfectly kind and respectful, were nowhere near the level of personalized service we have grown used to over the years. Nor were they anywhere near the level of professionalism at the CCR.

You still have to fly through LHR. If you are avoiding LHR, AA is not the way to go.

The differences between J and F on the 77W are worth thinking about and carefully considering. While on BA, the differences between CW and F are considerable, on AA's 77W, the differences between F and J are more nuanced. We would give serious consideration to flying J on future trips, and saving our money/points.