I confirm all of the positive points made by many of other guests.
This is a very friendly and convivial hotel. It's ideally located in a quiet area but only 10-15 minutes from St Mark's Square. Again, I can only support the comments about the afternoon tea, coffee, cakes, etc. A real plus if, like us, you've walked and walked around this beautiful city, particularly in the cold of December.
I'd like to make particular reference to Andrea, one of the duty managers. He was very friendly and a joy to chat to. I'm sure the other duty managers are good, but he's the man we met several times; he was a great advert for the hotel.
I have one disappointment. On our second night, the security mechanism on our door (Room 105) was defective. It would buzz at differing times during the night, as if someone was trying to get in. They weren't; it was a problem with the electrics, but it really disturbed our sleep. We pointed this out to the desk the next morning. That night, our third and final night, we were assured it had been fixed. We weren't confident, especially when all the lights fused when my wife was using the hairdryer. That was fixed and again we were assured the door buzzer problem had been fixed. However, at midnight and 1.30am again the buzzer sounded. We ended up having to move rooms in the early hours. This again seriously disturbed our sleep, and we were getting up quite early that morning as we were leaving. The hotel did respond with moving us, but it's a shame the problem wasn't rectified at the first reporting of the problem.
I'd still recommend the Hotel Una Venezia to family and friends.