My B/V Tornado is drilled approximate. 3.5" x 4.5". The cover is stock, plus some additional Finesse-it II polish.
I was expecting a tamer, more mellow reaction compared with my lightly polished V2 and Savage, but much to my surprise, the Tornado often seems very strong in comparison. It excels on medium lanes and drying lanes, often saving more for the backend than either the V2 or Savage. It also works well for me oiler conditions (probably due to my slower ball speed). However, it does lack the predictability of the Savage on heavy oil, and the V2 is easier to control on most mediums. But if you combine the Tornado's low price tag, potent back-end, excellent carry, and its performance on drying conditions, you'll find that the B/V Tornado is an excellent value, one of the better deals around.