OK it took me 2 tries to find this place, so at the end of this review I am posting really good walking/subway directions.
I loved this place. They were so friendly and I loved the buffet. So many choices. All kinds of mock-meat dishes, veg dishes, "boil your choice" veggies and tofu, like 8 kinds of soup, veggie sushi, dessert bar, and a tea bar with at least 6 kinds of tea made for you. Loved it. You do not need to speak a word of Chinese, either. Just grab a plate, and go to town.
Where: A ten-minute walk north of the Diwang Building on the west (left) side of Bao'an Nan Lu.
# By Metro: Dajuyuan Exit D; turn right on Jiefang and left on Bao'an Nan. You need to walk a ways on Bao'an Nan. After crossing Jiefang, you will cross a couple of small streets and at least one more traffic signal. The building is a huge one, on the left. Along the third floor on the outside of the building is a green and white faded sign with Chinese and also "Dengpin Vegetarian Restaurant" on it.
There are a couple of restaurants, shops, and a Buddhist gift store on the ground floor of the building. Go in the lobby, and go up to the 3rd floor for Dengpin.
Cons: Hard to find without good directions