We went on a family vacation to Seattle with two little ones (20 months and 6 years old) and this house worked very well for us. We appreciated the family friendly amenities (pack 'n play, high chair, diaper genie, box of toys) and the back yard. The house has a nice open and spacious feel to it, with lovely hardwood floors and a huge kitchen. We cooked quite a few meals there. While it does have everything you need, it doesn't have basic condiments (sugar, oil, herbs etc) so we had to buy all that from the nearby grocery store.
The house is located in a lovely residential neighborhood, walking distance to several playgrounds, a Whole Foods, and plenty of cafes and restaurants.
Communication with the hosts was prompt and helpful and check-in was super easy. We would definitely stay there again if/when we return to Seattle.