[Startrek (Martin)]

The Guide Assistant in PHD2 is not a magical wand to improve your guiding error or stability
It monitors your mounts behaviour during an unguided period of 2 minutes or more under the current atmospheric conditions and then directs the mount back to the lock position whilst measuring backlash and polar alignment error.
It only makes recommendations to correct noted problems with your mounts ability to guide or lock on to that guide star.
I’ve found it very useful but not a magical wand.
I use different mounts ( EQ6-R and EQ8-R ) under completely different locations and conditions and have used the Guide Assistant with varied results particularly with Dec backlash values and Polar Alignment values on the same night. This proves that guiding is a moving target to some degree dependant on atmospheric conditions which can change during an evening together with the specific location in the sky ( lower altitudes
I prefer to use the PPEC algorithm in lieu of the default Hysterisis algorithm in PHD2 and have found it has smoothed out my guiding with a marginal improvement in error.
I haven’t used Hysterisis in nearly 4 years
Unless you have severe inherent mechanical problems within your mount, I’ve found the following items to be of more value than anything else in regards to PHD2 guiding -
Opt for Ascom pulse guiding recommended by PHD2 ( not ST4 ) ie Laptop cabled direct to guide camera
Good Dec and Ra balance ( Ra balance slightly “east heavy” )
Use the “Wizard” in PHD2 to set up your rig and guiding
Create a Dark Library and save it / use it ( Wizard will direct you )
Use the profile tool to achieve reasonable guide scope focus
Get a good Calibration at Dec = 0 near the Meridian and save it in Auto Save ( I’ve used the same calibration for over a year , no issues at all
Try the PPEC Algorithm
Don’t fiddle with the settings of parameters , defaults usually work ok

Cheers
Martin