Alot of people on here are saying that if you were able to do or liked Expedition Everest, than Rock 'n Roller Coaster would be a breeze. I beg to differ. I have ridden both numerous times. I have ridden Everest four times in a row, but you have to bribe me (usually with ice cream or the promise of a future Dole Whip) to get me on RnRC.
It depends on what you do and don't like. It seems the OP doesn't like heights, but was okay with the heights of Everest and Splash. You don't really see the track too much or the ground at all during RnRC. Since the speed of the ride is constant throughout, you don't have 'drops' so much. BUT RnRC does have inversions, and many people don't like going upside down. There are three inversions, and the two that are next to each other are intense. There is also a launch; the 'limos' go from 0 to 57 miles per hour in under 3 seconds and exerts a G force of 5, which I'm told is more than Mission: Space exerts during it's simulated launch into space.
I love roller coasters. I looooooove inversions. I looooooove the speed. I loooooooove the drops and keep my eyes wide open on the Everest AND Splash Mountain drops. However, I hate the launch. I hate the force exerted on my body. I will not ride RnRC unless I've taken Dramamine beforehand, that's how scared I am of the G forces. Once I get past the launch, I enjoy the heck out of the ride. But I will not ride RnRC as often as I ride Everest or Tower of Terror solely because of the launch.