Dave-- The HSI page can be disabled in the Setup Menu, so you could just have the PFD and the Moving Map as your viewable pages.
Don-- The Mini-X can follow the heading bug (Heading Mode) and GPS track (ENAV Mode). It can also hold your selected altitude. However, you will not be able to climb or descend on autopilot. Climbs and descents are hand-flown, and then when you arrive at your desired altitude, you would engage Altitude Hold mode.
The Mini-AP has all of those features, plus it can climb and descend using both rates and airspeeds, level off & capture the altitude set in the altitude select window, as well as track ILS and GPS/LPV glideslopes. ARINC-429 is an option on the Mini-AP to enable tracking of vertical navigation equipment that uses ARINC-429 communication, such as a Garmin 430/530/650.
For those who are familiar with GRT Sport and Horizon systems, the Mini-X has the autopilot capability of the stock Sport without Vertical Commands software, while the Mini-AP has the autopilot capability of the Horizon HX and HXr. (GRT servos are required and not included...)