If you take any longer than .2 seconds to react/act to situations you should practice before ranked.

If you can't bring that down to at least .2 seconds your micro is uberbad and you should not be in ranked until you git good.

Pref .1

P.s. perhaps try a small-medium sized and or lightweight mouse for quicker micro. take note of where the lazer is located, I prefer it closer to underneath my index finger rather than in the middle around my palm area, while others may not.