In my opinion, it very likely isn't worth the extra cost. Why spend extra money to 'look' at the park, when you can actually 'be' in the park.
If you're like most people and will be in the park all day, does it really matter what your room looks out on to? We've had the parking lot view and the pool view at the DLH, and quite frankly, it was noisier with the pool view.
The parking lot view is also nice if you have little ones who can't stay up late enough for the fireworks, as you have a great view of the show and can listen to the music through your tv.