Paddle is a big concern for CW operators.
I have 3 paddles so far. No intention to add anyone to them. Though each is not perfect yet, I am always using Chevron. From left to right in the photo below, Chevron, Mercury by Bencher, Profi by Schurr.
I believe there are 3 major factors which determine the quality of a paddle.
The contacts between the lever and the fixed column side should be perfect. This won't be a major problem with these paddles. But Chevron sometimes has a contact problem between the column and the screwfixing the contact. Applying contact grease at the screw, I rarely have this problem. It is still sometimes annoying. Without this problem, this Chevron is the best. Chevron has upgraded to a new model, which might have been solved with this issue. Another paddle I used to use years ago has had a contact problem at the pivots of the levers. When contact seems not perfect, we should suspect of not only the problem with the contacts surfaces themselves but also the other parts described here.
2)Weight and resistence:
The lever weight and the mechanical resistence at the pivots of the levers should be as light as possible. The tension should be maximized when the lever is pushed as well. The movement of the levers are most important for paddle function. It should be as smooth as our hand. Yes, it should be an extention of our fist. From this point of view, the lever and the associated structure should be as light weighed as possible. It will minimize the motion resistence as well as the inertia. This is, however, contradictory to the following factor. The magnets make the characteristics of the tension ideal. The spring for tension as with Schurr is not ideal. All 3 of my paddles are pretty satisfactory as for this point.
I was pretty happy to have Mercury at first. It won't take me long to realize that it causes an uncomfortable sensation of rebouncing with that paddle. I guess the lever is so light that it causes a fine vibrtion proper to the system due to its striking to the fixed contact. That vibration should be felt as a rebouncing sensation. Increasing the tension and narrowing the contact spaces, it could be diminished to some extent. But it is not perfect. I guess the light weight, whether it was designed or not, should be the cause of this problem.
I still love these paddles.
No, I won't buy any more. Possibly.