I went there because it was nearby my hotel and not because of his ranking. This is maybe not the best Vietnamese ever but this is for sure well above average. Food is good, service is entertaining without being too intrusive. Prices are great. What else do we need?
So don't drive across Berlin to go there but if your are in the neighbourhood don't be afraid to push the door, you will not regret it! (Almost forgot. They don't accept credit card!)