Just thought I'd throw out a couple experiences as I am the new owner of a pair of CP3s and have used the BD carbon corks recently as well.
Like Jennifer, my one of my CP3s rattle and it definitely bothers me. I got in touch with Jotaro and we exchanged videos of poles and the sounds they make and he basically said that all of his poles rattle and the one I have that doesn't is the anomaly. So that's not ideal, but I'm still a bit torn as the CP3s are clearly more than sturdy enough for any trail and even some trickier off-trail walking and they are–of course–much lighter.
I was surprised how different it felt to carry them compared the BD poles. They are just so light and effortless. It made me want to take off the straps (which I swear by on the BDs) and just grip them. That got me thinking though that I'm pretty sure a lot of the weight difference between the BDs and the CP3s is actually in the grip and straps. The grips and straps on the BDs are much more robust and I wouldn't be surprised if in total they account for probably oz. of the difference in the weight (most of the difference).
So my suggestion to someone considering these would be to think less about the stiffness unless you do winter activities or really strain your poles and to think more about the tradeoff between a lighter weight and the much more robust strap and grip system on the BDs and similar poles.

