Is it better to do all the HP activities at Universal and then do all the HP stuff at IOA back-to-back in one day (as the sticky in this forum suggests)? Or just stay put for the day at Universal and then spend one day at IOA?.
Let me start with saying, the two parks are very close together, and it is quick and easy to switch between the two. There’s no real advantage or disadvantage to either approach, hopping or not hopping. However, there is a big advantage to visiting the HP sections during off times. HP during the middle most crowded part of the day is not the most fun. The shops especially get very crowded with only a few people, and it becomes hard to see or explore much of anything, much less really take in the details.
Try for first thing in the early morning or late at night before closing. It really doesn’t matter if you switch parks during the day or not, just avoid HP after lunch. You can do DA in the morning, then return to DA at night, or you can switch and do Hogsmeade that night. Same with IOA, you can do Hogsmeade first thing one morning, then break and return at night, or go over to DA instead at night. It doesn’t really matter. The only thing to note is that there is a Hogwarts Castle show at night, so I’d try for at least one night in IOA to see that.
My advice would be to do each area a different morning, and arrive as early as possible. I try for 30 minutes before official opening, as they usually open the parks earlier than the official time. Stay until the area becomes too crowded, then move on to a different part of the park, returning in the evening. This will allow you to explore with the most enjoyment.
For those who only really care about the rides, you can use single rider or the EP line almost any time during the day. Early Entry advantage is more for exploring, window shopping, and performing spells without long lines.
So I definitely recommend breaking up your HP visits into smaller chunks. The only time I don’t recommend this is when you are going solely for HP, have only one day, or are doing the Follow In Harry’s Footsteps thing. See the post below for instructions on doing that.
Harry Potter world as through Harry's eyes?
And if we do it all together, how long does that take? Probably a full park day, right? If we really want to take our time and admire the details?
There’s really no easy way to answer this question. The first trip we ever took, we spent 6 hrs in the Hogwarts area alone. This was before Diagon Alley was open and before the interactive spell spots. Thinking about it now I’m trying to figure out what we spent all that time doing, and I know the answer wasn’t waiting in line because we don’t wait for stuff. I think we did the Tour Only Castle Tour (no longer available), rode FJ single rider line, rode Flight of the Hippogriff, rode both sides of Dueling Dragons (no longer available), saw the wand show, bought a wand, sent mail by owl post, watched the Frog Choir and Twiwizard Ralley shows and posed for pics afterwards, explored the gift shops, and we ate lunch in the 3 Broomsticks.
Nowadays, however, we tend to be in and out very quickly, usually spending less than a couple of hours at a time. If you are simply going to ride the rides, especially in the morning, you won’t spend any time at all. However, really exploring everywhere can take a while. There’s lots of little things to check out that most people skip over such as visiting the Goblins to exchange money, stopping to listen at doors, calling the Ministry of Magic, looking inside the Triple Decke Bus, finding Kreacher, sending mail by owl post, posing with the Hogwarts Express conductor, trying different foods, candies, and drinks, or simply exploring all the details in the different windows and shops. How long you’ll spend, really depends on how much you decide to explore and how quickly you move while doing it. If you are content with simply looking as you walk past, you’ll be in and out in no time. If you stop to really look in each window, listen at every door, etc, you’ll be there half a day at least.