My experience with the Spirit was very different than most others.
I saw several other people with similar games to mine have good success with this ball, so I decided to try one. Mine was awful, hooked very little, hit was weak. I sanded it, and the 4 shots I threw were: flush, weak 10, bucket, washout (all decent shots on THS). Even though I was using a towel, the oil seemed to stay on the ball surface. I got rid of the ball soon after.
Several months later, I went to the Icon seminar. After the classroom session was done, I was able to talk to the Columbia rep (Danny Speranza, I think). I asked him about this ball, told him how it had looked so good, but mine was so bad. He let me in on a little secret. Of course the ball was introduced after 9/11 when there was a big patriotism/USA feeling. As such, the ball was made to be a good quality ball, even though the price was low. He told me the demand was much more than expected, and future batches of Spirit's were made with "whatever leftover material was available" (his words). So, he said, that my Spirit sounded like it was probably regular urethane!
Hopefully, you get a good one, and you should like it if you do. If you get one like I got, it may still be useful as long as you realize what it is. Good luck.