I use a DSLR, and for auto focus I use 10s at 3200 ISO. I use an exposure this long to even out the seeing, because bad seeing and short exposures can cause variable HFR readings, and jagged looking v curves. While the old routine worked well for me with both my Tak refractor and Edge, the new routine is even better, allowing me to start from a lot more out of focus position at the beginning of the night without the auto focus getting confused. I did increase my step size by about 25% with the new auto focus routine. I get beautiful, repeatable v - curves with both scopes, and for me the auto focus routine could not really be improved.
Dean