I had a chance to try the other upscale Vietnamese restaurant in downtown Palo Alto this weekend: Three Seasons. My opinion of Tamarine was fairly lukewarm (see link), and I'd have to say I feel about the same about Three Seasons. Prices seemed about equal. The atmosphere at Three Seasons is probably a touch more casual but it is still a rather pretty and fancy place.
Only two dishes impressed me at Three Seasons. The best by far was the mussels in tamarind, coconut milk, and chile sauce. The PEI black mussels were small and cooked just to tenderness. The sauce was excellent: rich, complexly flavored, with a good dose of spiciness. Disks of red chiles added to the heat. After the mussels were gone I spooned as much sauce as I could onto my steamed rice. The other good dish was the fried banana and coconut ice cream for dessert. The two slices of banana were covered in a gnarly crust of shredded coconut and then fried to a golden brown.
I found the spicy green beans only okay, though the other three at the table really enjoyed them. Most of the other food was quite flavorless and clumsily made. Pea Sprouts were crunchy and contained raw shiitakes. Summer rolls (California-roll-like modification of the Vietnamese cold salad roll) had very little crab and avocado, and lacked much other flavor. The cubes of meat in the shaking beef were overcooked and tough, and were accompanied by squares of limp yellow bell pepper. Chicken yellow curry was bland. "Happy buns" came with chewy steamed buns and dry duck, and lacked probably the most important element of the dish: crispy duck skin. I can't recall tasting fish sauce in anything, even the various dipping sauces.
Beverage service was slow: we were about half done with our main round of food before the bottle arrived (a good 20 minute delay). Glasses of Adami Prosecco di Valdobiaddene ordered at the bar provided a refreshing, tart green apple apertif. A bottle of 2001 Chinon Charles Joquet Cuvee de la Cure--with moderately complex aromas of cherry and earth and a strong, lingering tartness--provided a decent match with food, especially the yellow curry and mussels.
I thought the food was "okay" across the board at Tamarine, while at Three Seasons most were "okay" with a few good and few poor dishes. I'd love to hear more thoughts on what Three Seasons does well, and where it is better than Tamarine.