When you stay at a B&B, you are staying in someone's home, and you can never forget that. They always have more restrictive atmospheres than hotels. That said, the longer I stayed at Ca' Isabella, the more I liked it. It has the kind of plumbing that is unique to Venice, and it takes some getting used to, but it makes up for that by having an excellent location. It is not located on the main islands, it is on the island of Guidecca, just south of Venice proper. Because of that, it does not have the hoards of tourists roaming the sidewalks and alleys. Guidecca is more relaxed and comfortable. Hotel doesn't have a lift (elevator), and the rooms are not on the lower floors. They served a full breakfast every day, including meat. The people are pleasant, especially the older woman. The beds were comfortable. There is a public laundromat two bridges away, beyond the Palanca waterbus landing. Look for a "T" sign over a shop. That is a tobaccoist (cigarettes), and they sell waterbus tickets, each good for a set amount of time. We bought one-way tickets to get to the hotel 7.5euros each, two-day tickets for 30euros each, and one-way tickets to return to the train station.
From Palanca pier, take waterbus 2 to get across the lagoon quickly, or waterbus 4.1 to take a slower route to one of the San Marco piers. Make sure waterbus 2 is going in the direction you want. The list of stops and the direction is posted in every pier, but some piers have separate waiting covers.
