I saw many bad setups in reviews. Maybe it's true that the instructions are not clear? Impossible to figure out what exactly happens with those having problems if they don't show their setup. I trust eurogamer and roadtovr 100% for doing their homework. The others, not so much. Anyway from what I gathered from the more technical reviews, and from my experience with the PS3 move, these are my deductions:
Nobody really had these problem in the last year of demos at trade shows and across the US. These demos are usually setup correctly unless there's powerful lighting in the background (sodium lamps at bestbuy?).
Most have confirmed the ideal distance from camera is 5 or 6 feet (manual says the max is 9ft, showing the player and couch at 6ft).
Jitter happens when you get too close to the edge of the recommended area, or beyond.
Starts jittering when you're too far back, as it's reducing the spacial resolution.
Jitter/drift appears with occlusion. Placing the camera very low is a recipe for blocking the headset with your hands. It's much better to put the camera higher than lower, and keep you hands away from your face.
Some were in a studio setup with powerful colored spots. This could cause problems.
Strong lighting either toward the headset/move will cause tracking issues. Reflective surfaces can also be a problem.
Some of the reviews put the camera incredibly far, and are obviously caring more about making way for broadcast cameras to film the clowns.
Some are putting it low to the ground pointing up. The best orientation for resolving power is pointing perfectly parallel to the ground, at chest height, or head height when sitting. The Z spacial resolution doesn't look as stable as the X/Y, so it's best to avoid forcing it to resolve lateral translations of your head using the Z (happens with heavy camera angles).
Some put it on top of a slim TV on a stand, and that would wobble unless you have a solid concrete floor. It takes an invisible amount of wobble to cause a few millimeters of translation error. There's a good reason Vive recommends to literally screw the sensors securely on solid walls.
I noticed the old (square) camera will shake from vibration of the cable, the pivot point is too flimsy. I just glued it to the frame, and placed it flat on my (very heavy) center speaker.