I've been to this place lots of times on trips to Beijing. Partly because almost all of the vege places in BJ serve chinese food and after a while I want something different. The food here is Korean and they have several pages of vegetarian menu in the main menu (at the back). There are lots of korean favourites like bibimbap (not sure how to spell) thick rice noodles (more like tubes), stone pot rice dishes, noodles etc. Kim Chee comes up in many dishes so if you dont like it then be careful what you order.
The staff speak korean, mandarin and decent english. They understand vegetarian so you can ask questions- Im vegan so i had to confirm egg etc in some dishes.
I've eaten quite a few dishes and I do find lots of them a bit similar. Maybe because I tend to avoid vegetarian mock seafood which is in many of the dishes. I enjoyed the potato cakes a lot (have them every time), the glass/vermicelli noodles and the pork in stone pot.
The locaiton in nan luo go xiang is really good and nice for a night out where you want to browse some shops, go to a bar or cafe and have a meal in a place that closes much later than most of the vege places. It's more like a normal restaurant than other vege ones, bit cooler and a bit more upmarket feeling.Pros: Not just chinese food, Lots of vege optionsq, Nice location/place
Cons: Lots of similar dishes