Actually Crush N Gusher was the second. Adventure Landing near Jacksonville Beach has an uphill water coaster...close to the same size as one of the CnG slides.It was the first one in Florida though if we're looking for a comparison. The difference from the first to the second is going to be leaps and bound different.
The hydromagnetic water coasters are quite a technological marvel though. They're fun, fast, and highly innovative. I'm really excited to see where water slide manufacturers take things from here.