Is there some reason you're considering a standard room at the WL and not a VWL studio? Is it for the bunk beds for your kiddos? Just wondering, as a studio is obviously larger than a standard room (even though both BCV and VWL only have a sofabed as the 2nd bed), plus with a studio, you not only get the fridge, you get a microwave and toaster too. Always a plus, IMO!
As far as comparing one hotel to the other, I prefer the WL. I find that it feels cool in the summer (probably all that stone and water!) and warm in the winter. Plus, it's an MK resort, and you said that's where you'll be spending most of your time. You can either take the boat or the bus directly to the MK. Another plus!

Oh, and our ds loves taking the boat to the Contemporary to play in their arcade. In his preteen opinion, it's the biggest and best on property, and he loves that the games there award tickets to spend in their "store".
One thing to keep in mind about Stormalong Bay is that several posters have commented about how hard it is to keep track of little ones in such a large area. Don't know if that would be the case for you, but it's something to consider.
EDITED TO ADD: At the WL, you can also have a chance to be Flag Family! Getting to go up on the roof with Ranger Stan is a not-to-be-missed thrill -- it's still one of my ds' favorite memories.
