I was there yesterday for the grand opening...
First of all you have to take into account that it was the grand opening, which is why all of this took place...
We arrived at the auto plaza at about 5 a.m. and were let in at 5:30. We parked, walked through Citywalk and made it over to the front of IOA by close to 6. We were actually let into IOA at 6:30, but nothing was open besides some food vendor carts. From there, we walked from the entrance through Marvel all the way around to Jurassic Park, where we were stopped. Waited right outside the Discovery Center until about 9:30ish, when they finally started letting people into the land. The grand opening ceremony was right around 9:30, but I wasn't able to see it. By the time my group made it onto the bridge connecting Potter with JP, the line apparently stretched all the way out to the Hard Rock Cafe.
We got into the land at about 9:45 and headed straight for Forbidden Journey. It only took about an hour to wait for that because we were among the first let in. While in the queue for that, I did catch a glimpse of the stars riding Flight of the Hippogriff right next door.
The queue for Forbidden Journey was amazing and worth waiting for by itself.
I wasn't able to ride because the restraint system is ridiculously small. It wasn't even because I was bigger, it was because my torso is long and my shoulders are too broad. I was even told by a Team Member to go complain to guest relations so they would spend the money to make modified vehicles. I didn't get around to it, but by the sound of things, it seems like they got enough complaints.
After the ride, we decided to explore Hogsmeade. The line for a Butterbeer at an outdoor cart was over an hour long when I got in and probably close to 2 when I got out. I did try a regular one as well as Pumpkin Juice. Both are extremely delicious and worth the weight. I'd recommend getting one of each at least as well as the mug for your Butterbeer.
The shops were extremely packed and it was very difficult to maneuver around in them. In Honeydukes (the candy shop) it was very difficult to figure out where the line to check out began. It actually wound around the shop a couple times and took at least 45 minutes. They do have pretty much every kind of candy you'd want to try from the books as well as generic Universal candy shop fare. The Chocolate Frogs are delicious and the Every Flavor Beans have some good, and some really nasty flavors. Avoid the purple ones...
Because Olivanders was at capacity and they wouldn't let anyone else in because the line to purchase wands was ridiculous, we called it a day at close to 2:30. As we were walking out, we saw the line to get in the land went from the edge of Seuss Landing, wrapped around the lake and went all the way across to Marvel, then looped around again. If you were at the end, you'd be lucky to make it into the land before park close at 10. The Forbidden Journey Queue did indeed go up to 7 hours and they apparently used some of the Spider Man extended queue for it.
All in all, although it was an absolutely crazy experience, it was worth it. I'm a die hard Potter fan, so it was just awesome to see all these places from the books with such detail put into them. It's a must see for all vacationers.