We had a great experience staying at splendid star with Monica. The apartment is in a great location and very close to st Marks square. The check-in proccess worked great, though I think it would be difficult to coordinate without a working phone. I would highly advise getting an international plan anyway as its very hard and confusing to get around Venice without being able to use navigation on a phone.
Monica's apartment has a lot of charm with wooden beams in every room. There also are a few murano chandeliers as well, so the apartment has great character. The apartment was as depicted by the photos, though it was a bit smaller than I thought, but this isn't a big suprise given how old the buildings are. Just a heads up there are 3 long flights of stairs to get up to the apartment, which if your older could be an issue, especially with luggage.
For us though it was a pleasure to stay at monica's apartment. The location was great and she was very responsive as well. My one piece of feedback would be that I wish they gave you two instead of just one key. The apartment is very secure with 3 doors that need to be opened. However it makes it difficult as I went out while my wife was getting ready for dinner, and I couldn't take the key as she needed it for the power to work in the apartment. So it would be nice to have 2 keys if you needed to split up and meet at the apartment at different times.