Have it narrowed down to these two balls to replace my ultimax.   Please give your advice.

If you want a similar reaction to the ultimax I would recommend the mystic. I've thrown both and would rate them very similar.

Gotta be honest man; have the (actually, had-- just sold it) Mystic Aura.... was not impressed with it at all. Found it to be earlier (even with a 45x4.5x40 dual angle layout) and more aggressive early (even with surface taken up to 4k abralon, with polish applied) and less angular down lane than I had anticipated. Hence, why I sold the ball. Had it for about 5 months, tried multiple surface adjustments (from rough(er) 5/1500 up to 4k), polish, even added a weight hole to alter the roll........ never lined up with it.

Used it on multiple THS, tournament patterns, early block/late block, up boards/crossing boards....... never worked for me.

I haven't thrown the Ruckus-- own a Endless Nightmare, and while the endless is much earlier than the Ruckus, the Ruckus is stronger and longer down lane.

If you want something to take the place of the Ulti-Max, I wouldn't suggest either ball. I'd actually suggest the new Ringer (silver bullet anyone?)........... is longer and more angular than both balls off the spot, and I think (personal opinion) might fit what you are looking for much better overall than either of the new "high end" releases.

I'm not on staff, nor do I own a pro shop; my opinion isn't tainted by trying to sell you the "best ball" from the manufacturer.......... rather it is an attempt to get you a reaction similar to a ball that is pretty unique to the normal brunswick line-up.

If you listen, cool-- if not, cool as well. Check out the RG nums/Differentials/core shape/cover, etc. The ULTI was a neat, "unique" ball to the normal Brunswick line-up. Not easy to replace.

If you want another Ulti-- message me on here. I have a friend (pro shop operator) that has a bunch NIB at his shop that he's selling. Why update, when you can have a classic!

I gotta say the ruckus is a good choice for many.  I own most of the DV8 lineup and that ball is out of my bag more often than my Diva!

It is nowhere near as angular or long as they advertise though.  It does however get through the heads very clean (even when they're toast).  Gives you a solid midlane read and a strong finish. 

I do agree that if the look you want is angular.  . . A Ringer, or even a Misfit is calling your name.

If you haven't made a choice already, and you want to stick with DV8, I believe a Diva Pearl would be in order for your lineup. From what I have seen thus far, the ball is a strong pearl, but is not uncontrollable off of the spot.

Good luck in your search!

+1 on what he said.  That thing looks gorgeous from what I'm seeing from most.  Very smooth off the spot