We've tested the Berserk.
This is a really good ball for those typical medium conditions many houses put out these days.  It can hook, but you can control the breakpoint well with this ball.

It rolls quite differently from the Nomad Dagger which is actually good in my opinion.  I found the Dagger to be an awesome ball, it overlaps a bit too much with Storm equipment like the Hy-Road and Crossroad.

The Berserk is more of a rolly core, not exactly skid-flip.  It has just the right amount of continuity through the pins, deflecting the right amount.

See all the details, video, Digitrax analysis, and comparison to the Critical Theory at:
http://tamerbowling.com/index.php/roto-grip-berserk-bowling-ball-review-with-digitrax-analysis/

Let me know what you think.