Actually the difference between the DA and the Zowie´s is obv., which is down to MCU and Firmware, also you should know what g means in regards to acceleration.
The debounce time has been reduced a while ago, to nothing good, but also nothing bad. And no, enCoRe III isnt running well with 1000hz. Jitter can be caused not only by the sensor but also by the Firmware.
But the more important question is what kind of mouse you want, the FK1 and the DA are different in regards to grip styles, there are alternatives to both.