And I will say that the "backwards part" doesn't affect me in any negative way.
Its just another "thrill" in a great thrill ride.
People who ARE affected by these kind of things, usually assume that EVERYONE MUST feel "long-term" affects from any kind of coaster or other thriller.
But there are millions of folks who just "enjoy" the brief feeling (the "rush") and then have no post reaction (other than maybe wanting to "go again!")
I fall somewhere in the middle:
I can still "feel" the high-octane version of Mission:Space for 10 to 20 minutes after I exit.
But on EE, not ONCE do I ever get a "coaster feeling" during or after the ride (even during the "hair-pin" drop that's visible outside the mountain).
The backwards section's "secret" is how the angle and speed change the "gravity" of your body, but its just FUN for me... with no ill "feeings".
EE is the smoothest coaster I've been on.
"Intense" is a bit tougher to define.
If you are frightened in Snow White's Scary Adventures that will seem "intense".
If you are frightened at the film sitting in a movie theater, THAT also is considered "intense".
So, if the thought of riding backwards in the dark concerns you, then I suppose that will seem "intense".
But speaking of only the PHYSICAL MOTION of the ride, it is amazingly smooth and quiet compared to virtually any other coaster (including BTM, EE's closest "cousin" IMHO).
Its been my experience that "tensing up" during sections of rides that are unknown can affect me more than the physical forces of the ride itself.