The question is why would you want to make a correction of 0.1" when the seeing is probably never going to be better than 1.5"? Your mount will be trying to make unnecessary corrections that will never be visible. The fewer corrections you have to make, the better will be your guiding. See here
http://www.ccdware.com/resources/autoguidercalcv4.cfm for a good discussion.
Geoff