For me, the key basic test to a good beef Pho Tai is the clear broth base or soup itself with the spice mix but I don't care for the northern style with its sweetness, masking that "beef" taste. "Rare" thinly sliced beef flank, steak, brisket & beef meatballs - served with thin white rice noodles, onions, chopped scallions, bean sprouts - topped off with hot broth to finish cooking everything. Drop some fresh Thai basils (sometimes, coriander or Chinese parsley offered instead) and squeeze some fresh lemon or lime juice. Finished off with a nice iced cold Cafe Sua Da.
Southern California is the place for pho - called me crazy, we would drive 20 miles down to Westminster a/k/a Little Saigon just to get some with all that crazy LA traffic. It's 15 degree F outside now, wind chill near zero - I could use a nice big bowl - or, the hot & spicy, Hue style - Bún bò Huế ...
okay, dream on, time to get some work done.