BA gold is an important fact here. If you fly AA, it wil get you flagship lounge (first class lounge, a special lounge within the admirals club) access in JFK and lax, even if you are flying in economy.

If you fly in j, you will get 120 tier points for each segment on BA. This can add up quickly.

AA offers 3-class 767-200s on this route. All planes on this route offer wifi. I've never been in y on the route, but j and f are fairly decent by US standards (though not ncw level by any stretch).

An interesting tier point arbitrage is to fly EWR-lax, where AA offers only 2-class service. In the forward cabin, which is coded as f, you'd get 180 tier points each way. If you were to eurocheat, 5 segments and you'd be requalified for gold! Even if you don't, this is helpful to get to the 2,500 tier point level for the extra upgrade coupons on BA. The on the ground and in the air experience at EWR isn't as nice as JFK, but it's still ok.

BA gold won't get you anything in terms of upgrades on AA.

United also offers special 3-class planes on this route with economy plus in back - so you get some extra leg room. If you're in y, this could be nice.

Virgin america and DL also service this route. Co serves EWR-lax.

If you are a BA guy, however, probably best to stick with AA. Your on the ground experience will be great even if you are in y.

One thing to be mindful of, however, is I think not all fare classes in economy on AA accrue tier points on BA. I don't really fly in y so I don't know which, but you should look into this before committing if you are going y.

Fares are pretty high on this route right now. 2 years ago, you could get j for 1500 return, now it's 2500-3500 typically. Y is up a bunch too.

At these fares, premium cabin redemptions present a pretty good CPM value. I did one in AA f on the 3-class plane which was a 9 cent per mile valuation earlier this year.