According to BTM, the Disturbed has an overall rating of 54 and the Marvel-S with 54.  Seeing that, you'd have to look at the core numbers.  With the Marvel-S at 2.48 RG/.050 Diff and the Disturbed at 2.50 RG/.043 Diff means that the Disturbed's lower differential will read earlier and will probably give you something that is slightly stronger than the Marvel-S.

Honestly, I don't see either being a true step down unless you change one to a different layout (have one pin down/one pin up) and/or change the surface.

Well that sucks that they are both that close to the same numbers, that would explain what I am seeing. Thanks for the feedback, I picked up the Disturbed for $50, but after what I am seeing I should have gone with the IQ Fusion, like I had thought about.

The centripetal core is designed to get you predictable motion on fresher patterns.  I struggle with that core when moving left.  I use it solely on fresher patterns that I can't figure out, when I need to play up the boards.  I call that line, ’the norm duke line' as when I am using, I am usually playing where norm plays.

I was thinking about adding polish to it or seeing if my local pro shop would be interested in working a deal for something else.

According to BTM, the Disturbed has an overall rating of 54 and the Marvel-S with 54.  Seeing that, you'd have to look at the core numbers.  With the Marvel-S at 2.48 RG/.050 Diff and the Disturbed at 2.50 RG/.043 Diff means that the Disturbed's lower differential will read earlier and will probably give you something that is slightly stronger than the Marvel-S.

Honestly, I don't see either being a true step down unless you change one to a different layout (have one pin down/one pin up) and/or change the surface.

A lower differential means that the ball has less potential flare, thus in theory, less potential hook. A lower differential ball will also have the flare rings closer and tighter together, and retain it's axis migration longer.

The only reason that a bowler may have the Disturbed "stronger" than a Marvel S is because the Disturbed has a lower grit factory finish of 2000 abralon;  the Marvel S is at 3000 abralon.

The cover on the Marvel S is stronger, and the core is stronger. If a bowler is seeing a Disturbed with the same cover preparation cover more boards than a Marvel S, than it is do to the Marvel S slowing down too quickly. Board coverage doesn't always equate to "strength" of a ball. Often times, a stronger ball will cover less boards, and appear "weaker" because it slows down earlier than a ball with a less responsive cover on it. Storm seems to design their "strong" balls to hook early and offer more control on the lane, not necessarily cover a ton of boards.