眷村, juancun, are military dependent's villages built in 1940s and 1950s in Taiwan for KMT soldiers and their family members who retreated to Taiwan in 1949. The place's English name, Taoyuan Village, kind of misses the nuanced meaning that this place actually serves Mainland food, with recipes preserved by Mainland families retreated to Taiwan in 1949. For example, salty soy milk is dyed-in-the-wool Shanghai food, and that's not something special, that's what Shanghai people eat every single morning until the 1980s. It's one of the Shanghai 四大金刚---a nickname for four most common Shanghai style breakfast food. I grew up with my grandparents who are from Shanghai and they literally forced me to eat it because they thought it's tasty.
In fact I can't remember a good Shanghai place in Beijing. Some are decent but I don't remember any of these places serves breakfast---that's actually quite strange, and sad, because I and many others alike love breakfast, so this place is definitely a good addition to Beijing's food scene, though it claims that it's from Taiwan.
Sometimes places like this taste even better than the orginial food that you'd find in China. For example there are some really good youtiao and Shanghai food in NYC. Part of the reason is diaspora people tend to be more loyal to the original recipe than their home country fellows. For example Shanghainese places in NYC tend to put more wine in Drunken Chicken than most of the restaurant in Shanghai and Zhejiang right now, and I was told by a friend that it's acutally the older way of doing it.
Comarisons as such are very interesting and are the residue of history. For someone like me who grew up in Mainland, it was quite surprising for me to see that youtiao in New York and Taipei can taste so good, though being slightly different. It's hard to imagine that such thing would happen in the future with the whole world being wired by the internet and aeroplanes.