I rode a ZX-14 for five (5) years and it came OEM with floating rotors and fixed calipers. These rotors were of the two piece design, which I believe encourages radial expansion to dissipate heat, and facilitate the rotor alignment with the fixed caliper. If there was rotor/caliper noise, I never heard it.
As for cars, BMW included, I believe they use fixed rotors and floating calipers, as did Harley-Davidson for many years. Here the rotor is fixed and only one piston/pad(s) move upon brake application, forcing the caliper to "move" over and contact the other side of the rotor with the other fixed pad(s) on that side of the rotor. I replaced this arrangement on my HD with Performance Machine, fixed calipers and HD floating rotors (an accessory at the time).
This floating caliper/fixed rotor is fine for street use, but, as I understand it is prone to "fade" making this setup less than ideal for the track. Also, I believe the OEM rotors on our bikes are prone to warping from lack of heat dissipation, and whatever the cause perhaps a set of Brembo hat rotors would alleviate this problem. Were mine to warp, I would replace with the two piece Brembos.