Hi Steve,
I take exception to Tracy's statement about formation flying. I do quite a lot of formation flying and instruct every year at our clinic. The only thing you really don't want (and cant have) is a vernier. There is no need because the friction lock works just fine. However, a vernier would make any kind of quality formation flight impossible and could in theory be dangerous.
Quadrant vs. push-pull is a personal choice. I have never talked to anyone who flies with the left hand that has experienced even the slightest difficulty adjusting. Quadrants look cooler and are possibly easier to operate sometimes, but they are more expensive, and take up more space.
Consider this though. When flying a light aircraft with the left hand on the sick, the right hand is now free to work the throttle and, more importantly, all the other switches and knobs. Most radios are set up to be operated with the right hand on the control knob (which is mounted on the right side of the device). When using the left hand to say tune a radio or adjust the altimeter, your wrist now may block out whatever digits on the display that you are trying to adjust. I am much better at trying to tune a radio or mess with a computer in turbulence with my right hand. My left hand has no problem with flying the plane - that is gross motor stuff.
My cockpit is setup so that my right hand easily adjust all the knobs, switches and computers while my left hand never has to leave the stick and PTT button. I once flew an RV-4 with a quadrant and felt that I constantly had to switch from flying with my right hand so that my left could work the throttle, to flying with my left so that my right hand could operate the radios and what-not. Switching back and forth is far less than optimal, especially in formation flight when you occasionally need to make a quick adjustment of something. That experience made me very glad that I installed a push-pull operated with my right hand.
Dave Leonard