How is this supposed to work? Almost every thread I've read says Diagnostics adds the Sprite's rating as a dice pool bonus to tests to use the device, but SR4 says they roll Rating x 2 and each hit adds a die. Which is it? Also, if it's Rx2, do you roll that once and sustain the power, or do you have to roll that every time you make a test to use the item?
I kind of wonder if it was changed to +Rating(dice) in the SR4a. I'm using the older SR4 book.