Well, a 2BR at BLT will have 3 bathrooms. So will a 2BR unit at VAK (except for Value size accommodations) but Wilderness Lodge will only have 2 bathrooms. So, there's that.
What you will see in a "Standard View" room at BLT can vary; some of the views, while not of the Lake or MK, can be quite nice, overlooking the resort's greens and sometimes you'll even get a bit of the lake, too (if the videos at youtube are to be believed). With Animal Kingdom you will definitely be getting a unique an unforgettable experience as far as a view goes. Were I in your situation, I have 2 little girls so I'd opt for BLT so I could quickly and easily get to MK, plus monorail access to Epcot, and Poly and GF, PLUS boat access to Fort WIlderness and Wilderness Lodge, if you ever want to resort hop, dine in their restaurants, do Hoop De Do or the Poly Luau etc etc.. Once they're older I'd be more inclined to stay at VAK, but for now, BLT.