We love this place.
My son is only 13 months and I'm sure he'll love it even more when he'll grow up.
The water section is awesome, really allows the little ones to learn a lot.
The whole museum is just great, and their membership rates are WORTH IT, specially if a few friends can purchase it together and if you go pretty often. The only down side is that a single time entry ticket is $12 for any age... Meaning if you're coming with grandpa, grandma, hubby and two kids, that's... EXPENSIVE.