Ideal frequency processing

Buzz..

My circuit is a 555 timer responding to changes in capacitance of a HCH1000 humidity sensor. I managed to get the DMM reading from 200 Hz to 4 KHz (That timer was one swing away from lunacy coz I couldn't get the values right for a while for a readable frequency ), and I was wondering if my PIC should process the frequency better if it is larger or smaller in value.

Q: From 200Hz to 4 KHz, which frequency is best for processing with a PIC?
PS: I know that it CAN do at frequencies less than the value of the crystal oscillator, but I want some opinions before I solder the circuit away.

Makes no difference, that range is VERY low, and trivial for a PIC.