Our pal Brady MacDonald, of the LA Times Funland Blog, just tested the tweaked and relaunched Superman ride at Six Flags Magic Mountain and loved it.

I used to think the ride on the Superman shuttle coaster essentially ended when the car reached the climatic 415-foot-high peak. But now that Six Flags Magic Mountain has flipped the trains around to run backward, the fun is just getting started when you reach the top.
This is a great review that I highly recommend you read. While he absolutely loved the ride, he does have some tips and fair criticisms as well.

Six Flags Magic Mountain's Superman coaster review: Twice as good - latimes.com