Originally Posted by Perche

I hope you can see the big picture. You are not staying in Venice. You are staying far away from Venice. Even after your one hour train ride takes you to Venice, you will be at the train station, which is not where you want to be. With a 4 year old you will then need to take a vaporetto, cost around $25, to get to for example, San Marco, and that's a 40 minute boat ride. Possibly the child could get in free, but I don't remember the age.

Now, you still are proposing two places to stay that are not in Venice, so I don't know if you are not seeing the big picture yet. Venice has six sestiere, or six districts. Molina Stucke is not in Venice proper, neither is the Marriott. What are you continuing to propose to stay outside of Venice during your visit to Venice. Why don't you look for a hotel in one of the six sections of Venice, and stop looking outside of Venice? Venice is the best place to stay when visiting Venice.