We just got back from those exact days and had a blast. First of all, the weather was fabulous! We have been in May, August and September, and this past trip was the coolest we have ever experienced! It got pretty hot each day from about 3-5, but the mornings and evenings were perfect and breezy! I am usually sweating and miserable all day, and this was not the case on this trip! We said that when we go next year, we want to come the same week! As far as the crowds, it was really hit or miss. The beginning of the trip was much less crowded than the end. Even with the crowds at the end of the trip, everything we wanted to do was still very doable. We did not have to wait in long lines or anything, thanks to fast pass! DHS does get really crowded for SWW. We went Sunday of the first week, and Friday of the last weekend - lines for Star Tours, RnR, and ToT we longer than usual, but it did not matter with a fast pass, as long as you plan on staying all day! Have fun making your decision!