There are many possible logical explanations for what you observed. Here are a few (number 1 being the most likely culprit):
1.) You might not have been hitting the CB as low with the Meucci. Possible reasons for this are
tip shape and size effects, or stroke differences due to
cue weight, balance, and mass distribution differences (especially if you are an
elbow dropper).
2.) If the tip/cue combinations had very different
efficiencies, you might not have been giving the CB the same amount of spin and speed for a given tip contact point on the CB.
3.) Shafts of different CB deflections produce slightly different amounts of spin for the same tip offset. For more info, see
getting more spin with an LD shaft.
Next time, use a marked ball (or a stripe) to check the tip contact point on the CB after each shot. Also make sure the OB travel distance is the same for each shot (by hitting the OB into a spot on a rail instead of into a pocket) to ensure that the CB speed is the same for each shot. That will eliminate many possible misinterpretations of your observations.
Regards,
Dave