In my opinion, the Rival doesn't even compare to the potential of the Gamebreaker. You're going to get a much stronger backend reaction out of the Gamebreaker for the same amount of length. I was lucky enough to test the new Columbia balls when they came out, and when I tried the Rival, it just died on me in the back.
If you want to go with Columbia, then I think the Wrath High Flush would be a better choice. You'll get less performance than the Raid, but it definately has more backend than the Rival (from my personal experience with the balls).