I'm one of those still bowling with an X-Factor, and it has about 2,000 games on it. It's not quite the monster it used to be, but I still score great with it, it's in good shape for its age and it's like going bowling with an old friend. It's only had one full resurface, which followed a treatment in my dishwasher. Great ball.
I thought its reaction was very close to the Paradigm. As for the current stuff, I couldn't say.
Jess