Still in use in this particular social class. :) Since I'm not in, nor regularly associate with, the upper classes I am not sure of it's popularity there, but certainly lower and lower-middle use it although it is not as common as it once was. It is often abbreviated to 'sweet FA' where the 'A' can be interpreted as 'all' as well as 'Adams', I will leave the 'F' to your imagination.
Henry Minute Girl: (staring) "Why do you need an icy cucumber?" “I want to report a fraud. The government is lying to us all.” I wouldn't let CG touch my Abacus! When you're wrestling a gorilla, you don't stop when you're tired, you stop when the gorilla is. Cogito ergo thumb - Sucking my thumb helps me to think.