I've only stayed at the Marquis and did like it, but my comment is about something different - a block in back of the Marquis (not even a block, right across the street) is a huge open green area with a playground, tons of room for a 3 yo to run around, and even an indoor carousel IIRC. I think it's called Yerba Buena park. Rather than have to trek to green from a more urban location even just a few blocks away, this would be a great place to stay with a 3 yo.