gear ratio question

There are two combination. 20 pinion for 100 spur and 25 pinion for 125 spur. Logically same figure but maybe felling different? which one more punch? anybody try before?

Given the present day's motor output there should be no noticeable difference in the punch you can feel.  However, there is no point to use any parts which are larger or heavier than necessary.  Using a larger spur gear will also give you less ground clearance.  You may not be able to fit a correspondingly larger pinion gear to achieve the same gear ratio.  Lastly, the minor change in the motor position could also slightly affect the weight distribution along the centre line of the chassis.

Thanks for the advise.