Momiji is an apartment hotel, so there is a reception in the little lobby, so checking in or out is easy, as there is always someone nearby. Also the apartment was apprently recently renovated and everything was good and as expected. However, if you are not familiar with Japanese water heating, you might be surprised when only cold water comes until you turn the heating on, and the pronted guides did not include material about the water heating. Second small detail is that there was no guide in English how to use the washing machine or the lighting system.
My only bigger problem was that the listing gave a wrong address very close to Iriya station and I went there first. So I hope the address info gets fixed for the next visitor. Basically you will need to always walk around 10 minutes to get to any train, which is the only downside of this place. It is very close to Kappabashi street so if you are a fan of cooking, you will find it easy spend time perusing the stores there.