The Pursuit was dreadful for me. Actually, scratch that. The Pursuit-S was dreadful for me. It may just be me because I willingly went in for the symmetric ball, but I was more disappointed in the Pursuit-S than the Mission X, and both nearly had me looking elsewhere (read: Hammer).
The Challenge restored my faith in Ebonite. That ball is an absolute beast. They learned from their successes. The total/Complete NV covers were great. The One cover was great. The Mission/Mission Domination coverstocks were great. Throwing all of those into this cover makes this ball an absolute beast of a ball that doesn't bog down or use up its energy and faces up to the pocket early or roll out on broken down conditions.
Compared to the Pursuit-S, I'm roughly 3 boards left on a fresh THS, and getting through the heads cleanly. If you watch the demo video, I throw a line similar to Tommy's with a layout similar to his pin-up layout.
BL.