SimonV and I did a 'comparision' when Crush 'n Gusher first opened (with several rides on each, taking notes, and again each time we have visited) and we DID find a difference in the slides.
If you are standing facing the entry to the 3 queues, the queue to the extreme left is the 'easier' slide, the middle queue tends to throw the back rider over the front rider's head at splashdown, and the one on the right is the whizziest (but also usually has the shorter line).
Now, bear in mind that order is NOT the order you find yourself in at splashdown. The slides intertwine, so don't use the slide exits as your reference to which is the easiest.
Having said all this, it's still a dynamic ride. Great fun, but none of the 3 slides is exactly 'tame'.