the Hogwarts ride is impressive but made me nauseous (the line is long too).

Ollivander's Wand Shop wand show is overrated and the line is slow, but if your kids are 8-10 and really into it, they'll probably love it. My niece was chosen to be the model kid whatever they call it and she will never forget it. If you want to be picked for that, much better chance if your kid is in costume.

I went before the second half opened up, but my brother's family went last week and they had a great time at both sides. We did HP world for half day and the rest of Universal the other half. There's some cool roller coasters there if you're into that. You only have one day, it'll be tough to do all the HP stuff at both parks and have much time remaining for other stuff.