We have been this week for 4 out of the last 6 years. We always went to the parks from Saturday to Wednesday. It is always the week with the last weekdays before the SoCal passes are blocked for the rest of the summer. For those 4 years, Saturday and Sunday were always fantastic because the passes were blocked. The crowds were low and the lines were short. Monday was a crowded mess all 4 years, and Tuesday was not that much better. We still had fun, but it definitely was way more crowded than Saturday and Sunday. Wednesday the crowds had died back down and it was better, but I am not sure that the passes were still open Wednesday and Thursday like they are this year. The last 2 years we have been in July (including anniversary week last year) and both years I was really worried that the crowds would be horrible, but both years the crowds on all 5 days of our trip were significantly less than the Mondays and Tuesdays of the June trips when the SoCal were getting ready to be blocked. Doesn't sound like anything has changed since we switched to July two years ago (which was related to DD's schedule, not the crowds).
If the crowd predictors claimed that Monday and Tuesday of this week were going to be low crowds, they are crazy. We have 4 years of consistent experience with the crowd levels on those specific days that says that prediction was nuts. In all our years of going to WDW and DLR, the only time we have been in a heavier crowded day than those 4 Mondays was when we went to WDW the week between Christmas and New Years (well technically until after New Years) 1999-2000.
I would go this week of the year again IF we got the Saturday and Sunday because they were fantastic all 4 times. If I knew I would only be going this Monday and Tuesday, then after 4 years of experience with it, I would not just do those 2 days- they were consistently packed and crazy.