. . .
Chuck, when you press a paddle with a return spring the force INcreases with the path of the paddle
When you press a paddle with a magnetic return the force DEcreases with the path of the paddle.
That depends on whether the magnets are attracting each other, or repelling each other.
For the N0SA single-lever paddle:http://n0sa.com/?page_id=56
the magnets are repelling, on the _outside_ of the moving arms. So, as you press the paddle, the force (acting to keep the contacts open) increases
. That's what happens with a spring.
For some other designs -- for example, the Vibroplex Square Racer:http://vibroplex.com/square_racer.html
the magnets are attracting. The space between the magnets increases
as the contacts close, and the force decreases.
There's a distinct "clicky" feel with that arrangement (with wide contact gaps) -- not bad, but different from a spring.
With really narrow contact gaps, both springs and magnets have "nearly constant" force as the contact go from "open" to "closed".