A lot of this has to do with the swing on the ball even though just minor changes can make a difference as well as sometimes the ball is picked up by Trackman incorrectly...

I will say in a recent fitting the changes to the weights did not make a difference assuming I put the same swing on each weight...

Just my two cents...however maybe a Titleist Fitter online here might be able to say with exact details.

Hi, The balance of each Surefit CG weight is such that they only affect swingweight. Any secondary change of speed, or spin is due to the swingweight being lighter or heavier.

Thank you both for the replies, especially Cathi, was hoping to hear from you.

Cathi: That was the assumption I was wonder, as well as just about everyone one WRX, that the Surefit CG only moved weight internally side to side (or left neutral) or just dropped or added swing weight, and not moved the CG forward or back by changing the over all Surefit CG weight (hope that makes sense and I explained well).

The two videos are done by a well known teaching pro with tons of reviews on different clubs. In the video he does mention that he he prefers a lighter club's swing weight. I suppose possibly swing weight played a roll in comfort level. i guess I'm just curious/wondering why he saw the 400rpm drop in spin with the lighter weight.

Hi, The CG does actually move incrementally, but not enough to affect the drop in spin rate 400 rpms. He may have optimized his flight, or hit it with more of a right to left curvature which will lower spin.