This was our first visit to Dai Bi Chay. We're not vegetarian, but decided to give it a try because of the great Yelp reviews.
The decor is fairly standard for a Vietnamese restaurant. It's a medium-sized dining room with 14 tables (some for 8 guests) and seems clean and tidy.
We ordered the veggie spring rolls, which were tiny compared to usual vietnamese restaurants. There were 5 of them, but they were in a wheat wrapper instead of the traditional rice wrapper. They tasted quite good, but nothing special. They were served with a thick sweet chilli sauce instead of the traditional fish sauce (understandable as it's a vegetarian restaurant).
We also had the mango salad which wasn't bad. It had some sort of faux meat in it (not needed) and definitely needed some spice. We added sambal oelek which helped.
Lastly, we had the Hu style soup which had several meat substitutes in a fairly bland broth. It wasn't bad but other than being a bit spicy, there wasn't a ton of flavour. The noodles were cooked well, though.
The service was quick and friendly.
All in all, it was a pretty good experience. If you're vegetarian and craving Vietnamese food with mock meat to replace the real thing, this is a good option.