I went with AKV and here's why--
As you can see from my screen name, I have 3 kids, too. And while they are a bit older now, we were in the parks when they were the same ages is yours are now. And when your kids are that little, well, you don't do all day in the parks. You just can't. So your resort becomes a bit more important. Location is one thing, sure. And BLT is the closest to MK (which will be the main park for your crew).
BUT--AKV will be great because of the animals and the pool. The 5 and 3 year olds will be so into looking at the animals, I would think, that it will help with the down time. Also, since you will want naps and quiet time, AKV is more out of the way. BWV (which I adore) is so much in the heart of everything that I think quiet time will be harder to come by. With kids that small, you might like the remoteness of AKV.
And there is the pool. Nothing beats a zero entry pool when you have little ones. How wonderful for them to be able to walk in to where they are comfortable (and where you as the parent are comfortable). They can just sit in 6" of water and splash happily. Or if capable, can go deeper, etc. Not sure if the new BLT pool is zero entry or not.
But again, since I think you will be hanging out at the resort a lot, you might want to think about which resort has the best "hang out" factor, as opposed to which one is closest to the parks.
Like others, this is just my opinion. Truly, I don't think there is such a thing as a bad choice when you are choosing among
DVC resorts.
