We've done SWW the past 2 years (2009 and 2008). The PP is right - all special merch will be gone the first weekend, and sometimes the first day of the first weekend. It is hot, and it is crowded, although I thought that this year was far less crowded than last year's SWW that we attended. However, if you've never done it before and your family loves Star Wars, you definitely should do it at least once. Even in 2008 when we thought it was super crowded, we managed to ride Toy Story Mania (and it was opening weekend!), Star Tours a few times, have great seats for the parade, see Fantasmic, and get several character photos. I would imagine that most locals would attend on Saturday, so it may be less crowded on a Sunday.