This hotel is difficult to find. It's not a U.S. type hotel with a clear entrance with a clear sign. Instead, you have to notice that the address says "5F" and realize it's going to be on the 5th floor. There are no signs at ground level. There's just one small sign high above, easy to miss amongst many other signs that might say "O2 hotel". Hardly anyone knows about this hotel. And the ones who do know (competitor hotels), will tell you it's not here. At least, that happened to me. I struggled to find the hotel even though I walked directly to the block and knew it wasn't going to be easy to find and had stayed in this kind of hotel before.
But if you somehow know to walk into the New Mayflower hotel (near 7-11 and under the "O2 hotel" sign) and just boldly take the old elevator up to the 5th floor, you'll find your hotel.
Once you get there, the rooms are surprisingly nice. They look newly renovated, clean, and everything worked well, lots of power outlets and light switches. The breakfast (nearby at the Hedo hotel) was also better than expected.
In the end, I have mixed feelings. The rooms are quite nice for this price in Taipei. I like the breakfast and I like the area well enough (pretty active and close to the train station from the airport). The staff are nice. But the internet worked only intermittently for me. Overall, it's a reasonable choice for the price, assuming you can find it. I wouldn't send a friend without my directions.