In my Miata's, I used the 2" ball VooDoo knob in the 2002 NB and the "Tall" JoyFast knob in the 1991 NA. I much preferred the JoyFast. In fact, I much preferred the NA as well.
As for the 370Z, I am really surprised and happy with the Z1 M-Spec. It's well balanced and weighs about as much as the stock knob. I'm really impressed with how it feels in the hand.