I just bought a Vertigo about 2 weeks ago, and my game has been increased greatly. I used to bowl with a Brunswick Monster as my main ball, but now it's my spare ball. The Vertigo is great, it's very forgiving and when I hit the pocket, I REALLY hit the pocket. Before with my Monster, my high series was around a 625 and a high game of a 259. Since I got my Vertigo, I have thrown my first 700 series (a 711) and I've thrown 3 250s. My average was around 175 with my Monster, once league starts up again I think I'll be around 185-190 with my new Vertigo. Only problem is that the area between the finger inserts was damaged by the something while bowling, and now I have to get it repaired.
Once the oil becomes a bit lighter, I go to my Brunswick FuZe. And if that's still not fitting the bill, I throw my Monster with a slower speed.