From a family perspective...
So, I was going to take off a point as its not really an ideal place to go with little kids, but then again, if you are taking kids to Vegas anyway, I can't imagine many better options.
We paid for a room upgrade and then got upgraded even further as platinum Marriott members and the room was gorgeous. There was a large living room with a small kitchen area and then a large central dressing room that led into the huge bathroom and master bedroom that could be separated by a sliding door so we could be up after the kids went to sleep. We had a large balcony with a beautiful view of Paris and The Bellagio and we all enjoyed watching the fountain show at different times during the afternoon and evening from our bedroom, balcony, and even shower and separate soaking tub.
The 14th floor pool was our favorite but the views at the 4th floor pool were amazing too. Both pools had great soaking platforms with ample loungers were the water was maybe a foot deep. The pool was lightly heated which was nice as it was refreshing in the sun but warmer than the air when the sun was setting and the wind was blowing.
Staff were very friendly and helpful. Casino was much classier and more elegant than even the Bellagio or Paris. It was a great vibe and our kids loved it (special bonus note for having an actual crib vs pack-n-play for us). Overall, I'd much rather go there without kids, but for where we are in life we still all enjoyed it very much.