Tan Tan'a place is in a fantastic location. It's a 7 minute walk to Dunhua station. In the alleyways to and from the station are hipster restaurants, street vendors, mom and pop shops and convenience stores. Further out on the Main Street there are a lot of big stores. It's definitely a lively place once you step outside the building.
The building itself has 3 security points before you're in your room which is nice - building front door, elevator key entry and then the door to the place. There is also a concierge in the front lobby during the day. We didn't have any issues with rowdiness in the building.
The room itself is a little small. Id only recommend it for 2 people. The bathroom setup might be a bit challenging for someone with long legs as the toilet is very close to the shower. The room's feel was a little more like someone's house versus a hotel with mismatched dishes and such but they all appeared clean.
We didn't get the mobile wifi but we did use the in house wifi a lot. There didn't seem to be a speed cap which was great for making a video call back home or watching a video.
Lastly Tan Tan was very quick with responses which was helpful.