I've played a few Cannonball sopranos (straight and curved) over time. None impressed me. They were decent enough, but not to the extent where I reached for my wallet.
And, the differences among them could be attributed to the normal variations we experience when we play any brand. I doubt if Cannonball does much different among their models (like changing the dimensions of the tube) - doing that would substantially increase their costs.
Lastly, when someone comes on and reports that their one Cannonball did something different from another one, therefore ALL Cannonballs of that model will do the same thing - take a deep breath and consider the validity of such a claim. DAVE