They are so different and I love them both. The last two years and our upcoming trip are all split stays between the two. I like to start the stay at AKV to start relaxing right away. The resort is so beautiful and the restaurants are great. It is a completely unique experience. After leaving AKV, we do a slightly longer stay at BLT because of the location. I love being so close to the castle and feeling emersed in Disney. They is easy access to great resort restaurants from there.
So, I can't pick! They are both so great. Sorry I'm not any help. You can't make a bad decision, IMHO.