I'd vote for AK, and here's why:
1. Safari…'nuf said.
2. Rafiki's Planet Watch: a "behind the scenes" look at what CM and animals do on a daily basis…there's even an operating room you can look in on (last time we were there, they brought in a Stingray to check on her pregnancy).
3. Pangani Forest Exploration Trail & the Maharajah Jungle Trek: two separate experiences to see even more animals.
4. Triceratop Spin: a dinosaur-themed version of Dumbo…typically little wait time (at least it used to be prior to FP+). This ride is located amongst a number of carnival games…always an unexpected money-pit for our family, but our DD's (7 & 4) ALWAYS have a good time!
5. The Boneyard: an enormous playground and digging site for kids. However, patience and a good eye are required as the kiddos love to just run around…good thing though, it's a self-contained environment meaning a child cannot walk out on their own (so long as the CM manning the entrance/exit is diligent). This playground is less of a headache for our family vs. the Honey I Shrunk the Kids playground at DHS (seriously, I get heart palpitations there).
6. Finding Nemo the Musical: enough cannot be said at how amazing and entertaining this 30 min. Broadway-worthy show is!
7. the Tree of Life: the equivalent impact of Cindy's castle! A great, "I Spy," spot!
8. Mickey's Jammin' Jungle parade: hands down beats DHS current parade. Another great way to at least "see" a number of characters and some very unique 'floats.'
9. find Miss DeVine: your kids will just stare…parents will just stare…"what did we just see?"
I'm not sure of the height or fear-level of your twins, but there are several more attractions to see and do here. This park, when sensibly explored, can take you from opening to dinner time.
As for dining options: check Tusker House for breakfast (even the day before, especially with Disney's strict 24 hr. cancellation policy)…you might have success for a later reservation. However, breakfast switches over to lunch close to 11 a.m…so, if you land a 10:25 a.m. ressie, you could conceivably get a few breakfast items AND lunch items. Donald, Mickey, Goofy, and Daisy are there.
If you do select AK, ask a CM near the Tree of Life where the characters are meeting. Since "Avatarland" broke ground and the Festival of the Lion King theater is under construction, M&G's have moved around.
Honestly, either park will keep your little ones entertained…but, it's your trip as well.
Have a magical time!!!