Carla's place is very near to the Bus station and the Train station. The apartment is very spacious with a fully furnished kitchen and bathroom with a washer. The A/C worked great (for European standards). Carla gave us some bug suppressant pads to be used on a machine which we ran out and my daughters got a lot of bites one night - they slept with the windows open for fresh air. We wanted to keep the windows open as at night its not that hot but the bugs are a botheration.
Don't want to talk about Venice as it's AMAZING. The apartment is walk-able to all major attractions but you will be easily lost using paper maps even google maps as it depends on your cellular connection. But the best part of visiting Venice was getting lost - its magical. Ignore what people tell you about it being smelly, bad stagnant water streams with a LOT of people and bugs. Its worth it.
Overall we loved this place and would recommend to all.
One piece of advice is to either get a porter to move your bags on 4 bridges to reach this place from bus station or travel really light. Even to reach the train station there is a HUGE bridge (I really mean HUGE) to cross. I don't understand why would they make Venice so much tourist unfriendly when tourism is what is keeping this city alive. Only the bridges near St Marco Square have ramps build to make travel with suitcases easy.