Unlike others, I found my way to Truc Lam Trai easily. It's about 1 km south of Hoan Kiem Lake, but definitely worth going there.
For dinner I had fresh spring rolls plus a mushroom soup and deep-fried pumpkins from the daily menu. There is a much wider selection from there regular menu as well. All dishes were very well done. Including two fresh lemon juices I was charged less than 6 USD.
The service was friendly, attentive and discreet. Prices moderate, nice atmosphere.
I give them 4 cows, because I reserve 5 cows for exceptional experiences only.
Updated from previous review on Wednesday March 27, 2013
Cons: Tables may be a bit low for Westerners