We have waited to be seated at slow times and busy times - we only had to wait twice during
free dining out of our 10 table service meals.
I didn't see any connection between free dining = extra waits.
The restaurants are usually pretty full when we dine anywhere popular, and I didn't see a different in crowds either. We may have gotten lucky. Jiko, Kona, Concourse, afternoon tea, Spoodles all weren't packed. PSB, LeCellier, Coral Reef, Chefs, Raglan Road, 50s were all pretty full but they have been full at other times of year, too.
I think 1 hour is pretty short if you're going to eat 3 courses. If you'll just eat 1 course, then an hour is probably okay. We never factor specific times, though, and just go with the flow so I may not be remembering things right.