It's worth it if the view is important to you. We have stayed in park view rooms twice-1st time my husband and I chose it cause we wanted a great view since we had 2 days without park tickets so we figured we'd immerse ourselves in the atmosphere from the balcony. We had a great view of Grizzly River Run and loved sitting on the balcony watching people ride, etc. Also got a great photo of a hummingbird who joined us on the balcony. 2nd time we booked standard view but got a park view room as a free upgrade. It was okay, but I would not have paid park view for that room. It was in the corner of the resort so while yes, we saw the park, we mostly saw trees, the other wing of the building, and the monorail.
We didn't have any problems with noise either time. Also, CA closed by 10pm every night of our trip so even if it had been loud the noise would have ended fairly early, at least not to wake us up at night that is.
We're going back on Saturday and booked park view again. This time we did it cause we have a 2yo who never adjusted to the time change in DL at 6 months old nor in Hawaii at 20 months. Based on that, we figure she'll be ready for bed by about 6pm every night so we'll be spending lots of time in the room. We thought about doing DD view instead but thought we'd spend the extra on park view instead.
BTW, aside from looking at the GRR, Soarin', etc. area of the park, you can be overlooking the pool area and the Paradise Pier area as well. At least I'm pretty sure that's park view.