Hole in the wall - check. Stern (at times) owner who rules his roost - check.
I don't really trust a Vitnamese restaurant to be really really good unless it is a hole in the wall kind of place. :) And this place is good. Now, my one beef with this restaurant is the limited menu. But really, they do everything on the menu so well that you can't really complain. And the prices are extremely reasonable. Make sure you get the fresh rolls. I usually get the vermicelli with a little bit of everything on top. And unless you are ridiculously hungry, get the smaller bowl - it is still a lot of food.
BYOB, so feel free to bring your own alcohol of choice. I can't remember what the corkage fee is, probably because there is none, I believe. And bring cash.