Each bocal has slightly different characteristics. Better? Worse? Unfortunately, there’s no specific way to know unless you actually try and see how the bocal fits with your particular bassoon, reed, and embouchure. A dozen of the “same” Heckel CC2 bocals would all sound and behave slightly differently on your setup.
If you’re having specific trouble in intonation or evenness of tone across the octaves, my first recommendation is to have the instrument adjusted, if you have not had that done that lately. Sometimes what seems like a bocal issue can be a slight leak or maladjustment.
