dlloyd:
From first post:...the output being stable is more important. If it takes 500ms to update that is fine.
If 500 ms to update the output is OK, then at 5 KHz input you have 2,500 interval measurements to work with. Just adding those 2,500 readings then calculating the output will reduce jitter by a factor of 2,500.
I am reading down to 2hz would that not delay the reading a long time at low frequency?