For 7-8 years I was a T3 BA lounge snob, and still prefer the BA F lounge to the FL. But the AC vs the BA J lounge is a closer call, particularly in the morning when alcohol is not a factor. The BA J lounge can be packed and the AC seems to have more places to sit. Unfortunately with AA not offering F on many of its JFK flights, and my (hopefully permanent) demotion from OWE, I am consigned to the J lounges.