Monica was there at Rialto to take us to apartment, which is conveniently located for exploring Venice. Mario replied to all questions promptly.
One bathroom for sink, toilet and bath is a bottleneck for a bigger group, but we are aware of it before making a choice.
One thing is the washing machine outlet is into the bathtub, so you'd have to clean the tub a bit after a wash cycle. This isn't much of an issue also.