Marc, this handbook might explain a few things better
http://www.starlight-xpress.co.uk/Ha...0AO%20unit.pdf
As theo has mentioned the Mount has is not controlled by the AO. The AO is controlled from software either AstroArt or MaximDL via the Serial port. This requires that Maxim or AA also be used for Guiding. I am not sure if PHD or similar provide this type of control for the AO.
The only cosideration then is that your Guding Software be able to communicate with the AO.
The AO uses the information from the movmement/changes in the Guide star to adjust the optical path using the controlled mirror. Providing corrections that essentially improve the performance of your mount and Optics.
This chap J-P Metsavainio seems to be getting some excellent results with the AO and a Qhy8 combo. But this is on a Meade LX scope. The AO units have been known to improve the fork mounted scope performaces quiet a bit. The PE on these mounts is usually quiet high and the AO provides great improviement for this.
http://astroanarchy.blogspot.com/sea...tics%20(SXV-AO)
The SXV AO is great unit. It is quiet expensive compared to Sbig but it has the advantage of working with non SXV camera's. I dont think there is anything else in the Amature price range.