Moe,
Seeing the difference between 2 balls that are not supposed to be HUGELY different, I wonder if the difference isn't being caused by the amount of oil you using them both on.
The Ultra with its lower, RG, SOlid/Pearl combo AND its stronger Mass Bias rating should be earlier and smoother than the Twisted. SO either the amount & length of oil is better for the Ultra, given that you seem happier with it, OR it's too heavy for the Twisted, showing up in a a lot of saved energy and a huge backend and overall hook.
Since these balls aren't really far apart, with similar drillings, there might not be enough difference between them to use them as go-to balls. If, however, you differentiated them with a little of both, drilling & surface, they could be far enough apart to use them as go-to balls.
I'm making some assumptions here because I don't see how you drilled the Ultra and I'm not sure under what oil patterns & lane surfaces you tested both of them. I also wonder if by sanding the Twisted to 4000 grit, you're not bringing it closer to the Ultra, rather further apart.
Remember also the other item: house blended oil patterns can make ball differences seem either much smaller or much larger than they actually are.
Also try finer polishes on your Twisted as well as rougher (4000 grit) finishes.
Good luck.
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