The room was clean and comfortable, although the mattress and pillows were extremely hard for my taste. The lady on the staff who assisted us—I unfortunately forgot her name—was exceptional: very friendly, helpful, and welcoming. The hotel is also pet-friendly, which we greatly appreciated, and the breakfast was excellent.
The main issue was that our room was on the third floor and there is no elevator. Going up and down meant climbing close to 100 steps each time, several times a day. This was exhausting and, in my opinion, is something the hotel should address or find a solution for, especially for older guests or anyone with mobility limitations.
That said, if you are comfortable with the stairs, Serenissima is an excellent place to stay. It has a great location, wonderful staff, excellent breakfast, clean accommodations, and the added benefit of being pet-friendly.