Spoiler alert: I only have good things to say about our stay at Mia's place.
The flat: two comfy beds, each in its own private room give ample personal space. The bathroom has great water pressure and the shower has ample hot water. It's equipped with everything you need, including a rice cooker, microwave, toaster oven, tea kettle and coffee maker. Even the towels are fluffy. Everything you need for a great stay is provided.
The building: Turns out there is an awesome view from the building's rooftop, especially fun for planespotting since you're close to the approach path for Songshan airport. You can see Taipei 101 too!
The location: basically ideal. Right across the street from a delicious bakery, surrounded by markets and convenience stores, and half a block from a local night market. Only three stops from Taipei main station on the red line.
The host: Mia was great throughout. Easy communication, painless check in, and we were even allowed to check out a few hours late since we had an afternoon departure.
By the end of our 10 days it really felt like home. We were sad to leave it behind!