I don’t think anyone can answer this for you. You know what you’re looking for in a resort and when your family travels versus what we’re all looking for when we travel.
However, you asked, so here is my take on it.

We are a family of 4, but my kids are 8 and 6 (close in ages to yours). We own at BLT, VGF, and RIV. I will admit that theming isn’t important to us at all. Location and/or
feeling upscale (for Disney) are important to us. The extra bathroom at BLT and AKV is hard to beat. If you want to stretch points but love theming, I’d say to buy at AKV. If you want to be close to MK, I’d honestly look at BLT for the 1BRs over Poly, but that’s a personal preference. BLT isn’t great for theming, but the location is hard to beat. We’re staying in a 1BR at BLT this summer with the kids. The nice thing about BLT 1BRs is that there is a sofa bed and a fold out single bed in the 1BRs and 2BRs in addition to the extra full bathroom. We’re staying in a 1BR for 36 points/night at BLT this summer. It is 23 points/night per studio at Poly which would be 46 points for 2 studios. That’s and extra 10 points per night for Poly. Not worth it IMO, but it’s just my opinion.