Most of my cats have a seemingly normal reaction to it but one of them just kinda lays there. She goes limp and lays perfectly still until she is moved away.
When I give her the dry loose stuff, she mostly just gets all poofed up and zoomy and bitier than normal. She also has a rainbow catnip toy that she spends a lot of time licking, but this doesn't tend to make her wig out as much.
sadly my cat hardly ever even eats cat nip anymore, but we used to have a cat who was so obsessed with it he would roll all in it and then roll all over the floor. there were a few times he would just belly slide along the floor through the rooms to the other cats' catnip stash. if we ever needed to find him all we needed was to shake the container and he'd rush out instantly.
My cats go nuts!! They roll around on it, eat it, run down the hallway and back to the cat nip. Lol :)