Well, I can't blame a restaurant for its soy sauce or its prices, when the food is of such good quality.
You'll find many variations on mock duck and tofu. Whereas the variety isn't as large as what you'd find at Evergreen, for example, it still takes up a page at the back of the menu, and is entirely without fish sauce, which is refreshing.
It is a bit pricier than your average Asian restaurant in the Cities, which will surprise you, given its spartan appearance, but I find that the extra cost is worth it. For example, something similar that you'd find for $8-9 someplace else would go for about $11 at Huong Sen. Also, it should be noted that the prices listed in the online menu are from around 2004-2005, so most things are more expensive today. However, instead of being served a bunch of bland filler vegetables (i.e., carrots & bamboo shoots) smothered in gravy, you actually get a whole bowl spicy mock duck, for example, and a separate, smaller bowl of rice.
Service is efficient and polite.
They also have bottled and tap beer ($3-5 range), as well as just one plum wine.
If you're in the St. Thomas or Macalester area, it's worth a try.