Overall, our stay at Susan's place has has been great. The flat's very conveniently located on the route from/to the airport and the city centre is just a few minutes by tram/bus or on foot. The flat is clean and equipped with modern furniture.
The only thing we were missing were additional blankets that unfortunately weren't provided when we asked for them. Also, we didn't expect having to buy our own toilet paper (as the provided quantity was definitely not enough for four people staying for five nights).
Although we haven't met Susan in person (the whole stay including check-in/out was fully automated including what seemed like template messages throughout our whole stay), her responses were blazingly fast.
All in all, we recommend Susan's place and Edinburgh is a beautiful city worth a visit!