I have never seen convincing evidence of this. For all practical purposes, regardless of the type of cue and type of tip, if the tip contact point on the ball is the same in any comparison (assuming the cue elevation is also the same, and the stroke is in the same direction, and there is no miscue), the amount of spin delivered to the CB should be the same (or extremely close).
Now, with a long shot, if you use the same stroke "effort" in the comparison, a heavy cue with a hard tip might create at different reaction off a cushion as compared to a light cue with a soft tip, but that's because the CB might have different speeds in the comparison. Since side-spin wears off over time, the slower shot will lose more spin before it reaches the cushion.
For more info, see the getting more spin with an LD shaft resource page and the tip hardness effects resource page.
Regards,
Dave
I understand your logic, but it doesn't account for the masses of players (me included) who find certain cues spin the ball easier, while some cues have almost no life at all. Next time I come across a truly dead cue, would you be open to testing it?