The 2 nights we were at BLT, the observation deck was surprisingly, not that crowded. On one night, we viewed "HalloWishes" fireworks on Halloween, and there were probably 50 people there. Considering how long the deck is, we didn't feel crowded at all! However, we did stake out a spot about 15 minutes beforehand (even then, there were only 4 families waiting).
Don't get me wrong, if you can and want to swing the "view" rates, go for it, at least once! All I'm saying is, I've "been there, done that," and realize that for my little family that the view isn't all that important because we're barely in our room.
Happy travels!:wave: