I've never tried it, so I can't say that it's good or not.
DH emailed me a recipe from NY Times Cooking section. (NYT Cooking requires and account to directly access - I don't have one or I'd post it for you.)
The broth is :
3lbs bones and 1 lb brisket
1/2 Fuji apple
onion, ginger, star anise, cinnamon, cloves, fish sauce, sugar
30 minutes in the IP, 20 minutes in a traditional stove-top pressure cooker
Traditional toppings to serve:
6 oz thinly sliced beef steak (sirloin, eye of round, I'm using tenderloin)
rice noodles
cilantro, chilis, etc.
The apple is a little non-traditional from what I've seen in other recipes, but the rest looks pretty standard.