I am about 40 min from both Mystic & the Dinosaur place.
We were members to the aquarium for the past 2 years so I didn't renew.
The Aquarium usually has the Birds of Prey exhibit & it opens at 10. I strongly suggest getting to it at 10 because the birds are hungry then. If you wait until 11 they most likely won't come to your stick of food. They get another hunger pain in the afternoon but I am not exactly sure what time.
My kids loved feeding the birds, even my youngest who is now 3.
They also love the sting ray exhibit & I usually make that last because they will stay in there for a good hour (or it seems like an hour) trying to touch them.
The shops next to the aquarium are cute too. And I can spend all day there just window shopping.
I haven't been to the seaport in at least 15 years but my sister & her dh went last summer & they liked it.
We haven't been to the Dinosaur place in probably 2 years either. My kids like it. I wasn't sure what to expect when we went the first time. But it was sticker shock!
They did the sprinkler park & it is pretty big. We walked the trails & saw the fake dinosaurs. They loved the playground too & I thought I saw that they were adding something new this year in the Mystic magazine I got a few weeks ago.
Places to eat, ack, since we are 'local' we don't go & eat. We either eat at McD's or the Aquarium (10% off for members). But there is The Steak Loft, I am thinking The Ground Round. Something seafoody (this is across from the aquarium).
Here is a link to a touristy map:
http://www.lighthousemaps.com/Mystic/MysticDTindex.html