I finally found some Mochiko and started testing. Mochiko is slightly grainy in texture, while Glutinous Rice Flour (such as Erawan Brand) is very fine, more like talcum powder. I baked two batches, one with Mochiko and the other with Glutinous Rice Flour. The Mochiko batch was very cake-like and quite risen. It also did not bake in the center, but remained quite raw. The batch made with Glutinous Rice Flour did not rise. It baked all the way through, developed a nice crust and was very chewy when cooled. This leads me to believe that Mochiko and Glutinous Rice Flour are not the same thing.
And yes, it is incredibly addicting. I much prefer the Glutinous Rice Flour version. I guess I'll have to work out twice as long to burn off the carbs...