Okay TFW members, I need to call on your parental wisdom here...
So, I wasn't even planning a trip to AK in May. Now my DS's been watching last year's WDW planning DVD endlessly and has announced, (among other things

), that he wants to ride Dinosaur.
Me:

"Dinosaur"? The one where TRex looks like he's coming right at you?
DS: Yes. I wanna ride Dinosaur.
Here's the thing - DS will be 5 in a few weeks. Yes, he meets the height requirement, but I'm frankly worried about the aftermath if I let him ride! He LOVES thrill rides - he's a coaster fanatic. But the 3D movies terrified him so much, I literally had to drag him, crying his little heart out, into Carousel of Progress, so great was his fear that something was going to "come out and get him". And he has nightmares fairly regularly from watching the POTC movies at Daddy's house. (Don't even get me started on that one.) Can you see why I hesitate?!
On the other hand, I know I need to sometimes trust him to know what he can and can't handle. He's never been wrong before. But I'm not so sure this is one of those times.
Can I get some opinions on the subject? Anyone gone through this personally?