I had a Quarter Stick in my Cordoba. From a quality standpoint, it's a very-good, well-built shifter. From a driving standpoint, I would recommend you drive one first if you can. It's got a good, solid feel to it but it can be a bit of an annoyance to drive on a daily basis. There's a lot of messing around with that trigger lever; it's a vertically gated shifter. It doesn't ratchet (which is one of the reasons I chose it--I hate ratchet shifters). If I recall, once you've got the Pro Stick in Low, you squeeze the lever to shift to Second. Releasing the lever will get you into Drive. Squeeze lever again, and you can hit Neutral. Engage a separate lockout lever near the base to get Reverse, then another squeeze to put it in Park. Parallel parking could be murder with that thing. I would use one again in a race car, but I wouldn't put one in a driver again. I sold it to a friend who put it in a mud-bog truck, which requires a lot of up-and-down shifting; he ran two events before he removed it. The only advantage to that shifter was that my wife couldn't figure out how to drive the car.
I have no experience with the Cheetah, but I've driven numerous others such as the QuikSilver, MegaShifter, etc. If you don't mind ratchet shifters they're OK, but I would tell you to reinforce the tunnel in the area of the new shifter. It flexes a lot if you don't, and it ends up with a junky feel--and I'm not one to hit the shifter with a lot of force, either.
As far as floor shifters are concerned, I think the factory Slap-Stik is the only way to fly. I've always been curious about the Z-Gate from B&M because the description sort of makes it sound like the Slap-Stik style action, but I've never driven one. I would still recommend the floorpan reinforcement if you chose the Z-Gate route.
