I hate to be this blunt, because I know it makes me sound like a jerk...but YOU are the grownup. YOU are paying for the trip, I'd presume unless your kids are child models and you're using their income. Your kids will be 6 and 3 and they're going to Disney World. Chances are, more than likely, they're going to be thrilled no matter where you stay, no matter what you do, and it will be YEARS before there's a thought of "wait, we could have done THIS and stayed HERE instead while we were there?"
Stay where YOU want to stay. Do what YOU want to do. They will more than likely have just as fine of a time - and at times be just as upset because they'd rather be over THERE doing THAT instead of HERE doing THIS - as they would be if you made an effort to cater every nanosecond of your trip to their whims and fancies.
Would your kids' minds be blown walking into AOA and seeing those giant statues of King Triton and the like? Yes, no doubt, and if you got a suite, they'd probably feel like they were living in the world's coolest clubhouse. And just as likely, they'll be exhausted and miserable the days where buses take forever to get them to a park, or back from a park, and make you more exhausted and miserable, too.
But most of our past trips have been spent, in part, at the DVC section of the Contemporary resort, Bay Lake Tower. One of those trips, my kids were close to the ages yours will be, my older was 6 and my younger was nearly 3. And they went batpoop crazy eating in, of all places, Contempo Cafe, because they got to see the monorail roll by (and believe me the batpoop craziness went to 11 when we actually dined in Chef Mickey's right next door). The idea that we're walking or taking a monorail to Magic Kingdom is what blows their mind. Every time I've awakened them or let them stay up a little later so they can see the Water Pageant is one of their favorite memories. That resort is so Disney to them, on one vacation where we didn't stay there, there was straight up legit separation anxiety (it passed, haha). For about a year after that particular trip, my younger would ask me on a fairly regular basis: "Daddy, maybe this weekend...we can go to Disney? And we can go to the hotel? And swim in the pool? And I can go down the slide and you can catch me?" That little baby slide at the Bay Lake Pool, a slide where many times she had to scooch herself down in order to get to the bottom was one of her biggest memories for a long time.
We spent a night in Art of Animation once, in a Little Mermaid room, having driven and arrived a whole day early. And they enjoyed it, especially the pool. Mom and Dad having to squeeze into a double, not so much. But if I ever talk to them about going back, they always ask if we can stay at BLT. It's never giving in to them because it's where *I* want to stay and they're along for the ride.
Contemporary rooms are significantly bigger (unless you get a suite at AoA). You're walking distance and monorail rides away from 3 character breakfasts and some of the best/most fun restaurants on property (to say nothing of the boat ride away to Wilderness Lodge and Fort Wilderness in case you'd like to go to Hoop De Doo Revue one day). Hell there ARE restaurants on property, not just a cacophonous food court. You've got watercraft rentals and cool pools and great views and when you're at MK and want to take a break, you're a monorail stop away. You also have monorail access to Epcot. Any kid that you give that to, if they ever turned around and said "yeah, but I really would've preferred that pool where you can hear the music underwater," write those ungrateful curs out of your will.