I appreciate all the advice everyone has given me. I keep getting hit with decision paralysis. It's comforting to know that I can use my points to stay wherever I want, but everyone keeps harping about "buy where you want to stay" which I totally understand. And I think I definitely would say Poly wins out over BLT for myself and my family.
My daughter is only 2.5 but is absolutely in love with Moana--not sure how long that will last but I think the theming would be a big hit with her. My wife and I also honeymooned in Hawaii, which we loved (our only complaint was the travel time to get there from Chicago). While we'll probably go back someday (hello Aulani), getting "a taste" of tropical life when we go to Disney would be very special for us. Other things like the pools are probably a wash--our kids are going to love whatever pool there is. The walk to MK from BLT sounds so so so amazing, and it would be a fine consolation for us. Hell, maybe after doing it once or twice, I'll wonder why I'd ever want to deal with the crowded monorails at Poly

I think in theory, I'd love to get an 11-month booked at Poly and then we could discuss "saving" points by seeing what BLT has at 7-months.
However, the fact that Poly points:
A) Cost more (BLT contract at $123/point, Poly contract at $163)
B) Don't go as far
keeps bringing me back to BLT!
The downside to this is, I'm not sure even a 2-year cycle (effectively 320 points) would get me as much wiggle room at Poly. We'd primarily travel during travel period 5 (October/November for son's birthday, wife's birthday, and
MNSSHP), or travel period 6 (when it's winter up north, daughter's birthday is March). A studio will be anywhere from 160-248 points depending on view, and the 2-bedroom 450-700 depending on view (so I'd either need a bank and borrow situation to get a 2-bedroom at Poly, or I'd need to buy more points down the line).
Meanwhile at BLT, we'd easily have enough for a Studio every year without banking or borrowing, could easily get a 1-bedroom with banking, and would only need the smallest amount of "bank and borrow" for a 2-bedroom.
Am I crazy to consider a resale contract for Aulani or AK? I'm seeing one for Aulani that is 250 points at $99/point and at AK for 270 points at $99, which is going to run me the same cost as 160 points at Poly. Yes, the dues are roughly $2/point higher than BLT and $1/point higher than Poly. I'm sure that can/will add up. But if I want to risk 11-month availability and book WDW Resorts at 7-months, I'd have far more to work with to secure the room type I want. Also, I imagine we'll go to Aulani at some point in the future, but we'd probably wait at least 5+ years until the kids are older and could appreciate Hawaii more. On the flip side, we'd probably actually stay at AK at some point. Especially because the 2-bedroom SV seems super affordable from a point standpoint. I hear many great things, my only gripe is having to use bus transportation exclusively.
All in all, I feel the cost discussion comes down to "how much do I value the 11-month booking window", which I think only you seasoned/veteran DVC members can answer for me! It seems like the general consensus is to always make a booking at the 11-month mark, and then explore other options at 7-months, so choosing a home resort is all about picking a resort you can fall back on (if nothing is available at 7-months) and be happy with.