I fully expect it to be more "coaster-ish" then Mummy, but not crazy like DD or Hulk. Im expecting a 4/5 Thrill level. Where Forbidden Journey is closer to a 3. Which is also where I would rate both Space Mountain and Spiderman. Of course it's all up to personal experience and preference. Universal Studios has more kid friendly rides then Islands does, so I am expecting the new Potter ride to help even that out.
Not to mention, you may notice that the more thrilling rides seem to have the longest waits (except maybe DD, which is always a short line due to how quickly it handles capacity)
Space Mountain may be a little more thrilling because it's not simulated, but simulated rides are still very thrilling.
One last thing....I keep seeing "Coasters? That's what Six Flags is for"...you guys do realize that there is no Six Flags in Florida right? The closest thing we have to Six Flags is Busch Gardends, and that is abour 3 hours from Orlando.