The crowd levels are just guesses, in some cases good guesses but guesses none the less. It really depends on your travel style and what you want to get done. We are not rope drop people, but getting there at rope drop will allow you to knock out 2 or 3 or even 4 rides then you can book your FPs for a little later, say 11 or so on the more popular hard to get rides. We tend to be late afternoon evening people, so we get to the park when we get to the park, walk around and ride the rides we want to ride and book FPs while we are in line for other rides. Again, it depends on you style and what you want to get done, are you planning on going back at any time, do you have park hoppers are you rope drop to close, etc. We go often so are wing it type of people, we were there the week before Christmas and booked no FPs or ADRs in advance, we booked ADRs either the morning of or while walking around. We booked a few FPs while standing in lines but otherwise we just decided if a line was too long or not and moved on but we go with the attitude that there is no way we are going to see and do everything there is to see and do so we just make the best of what we can do.