With the exception of Wizarding World of Harry Potter, the parks were comfortable when I visited first week of October. I went to the park solo, and was able to ride Rip Ride Rockit six times in 30 minutes.
Other sections of Studios was not really crowded, but when I got into Islands of Adventure, I could actually feel that there were more park guests at IOA. Quite impressed with Potterland but at the same time it was quite busy. But that's what you get when you have a new attraction that is still fresh in the minds of many.
The Forbidden Journey did take about 30 minutes to cross through for the first time, but I wanted to experience it all. After the first time through, I made a beeline for the single riders line and was back on the ride in 5 minutes tops.