I'm not Vietnamese so I don't know what's authentic or not, but what I had was pretty darn tasty and the serving was very generous. The small is probably equivalent to a large elsewhere IMO however price wise, it's also closer to a large elsewhere. Our table of 3 decided to try 3 different types of soup base - Original, Thai style and Satay. They were all very good. My favourite could possibly be the Thai style. It's a tom yum type soup base and it yummy with pho noodles. No extra hoisin and sriracha sauce required. Service was great too. The waiter (possibly the owner) was checking on us often to make sure everything is up to par. The basil leaves and bean sprouts were so fresh too. I'll be back for sure because I've been eyeing the bowl of vermicelli at the table next to us.