Ahead of the opening of the Xinzhuang Line extension to Danfeng and Huilong this Saturday, the New Taipei Transportation Bureau predicted that the two stations will attract 21,000 rides a day (7,665,000 a year). This isn't very good compared to the ridership numbers for the Xinzhuang Line last year, though at least neither station is likely to end up in the bottom ten.
In the same article the Transportation Bureau also claims that from Huilong to Minquan W. Rd. will take 22 minutes, and to Zhongxiao Xinsheng will take 28, making taking the MRT faster than taking a bus. There are a few problems with this though: for one thing, not many people want to go to those two stations, and because the Xinzhuang Line goes all the way to the Taipei Bridge before entering Taipei, the MRT will actually be less competitive for people going to some more popular destinations, especially Taipei Main and Ximen. In fact, two of Taipei's five most popular bus routes in 2011 took more direct routes to link Xinzhuang to Ximen and Taipei Main, showing that those routes, and not one that goes all the way to Minquan W. Rd., is where the most demand for Xinzhuang-Taipei transit is. Furthermore, part of the goal of the MRT should be attracting drivers rather than just replacing buses. It should be a given that the MRT would outpace buses, the real question should be is it faster than driving.