I am flying from KLGB to KMCC in the G36 right now (with the performance improvement mod, but that shouldn’t change the AP behavior that I am aware of). Preset NAV mode and FLC at 100kts, altitude bug to 8000ft before takeoff but did not engage AP.
Took off, got the plane established in a climb at ~110kts, and hand flew a heading with my intersecting GPS NAV course at a shallow angle. Engaged AP just before the intersection. AP captured the NAV heading and pitched up to the 100kt FLC climb speed, then climbed to 8,000 ft and leveled off.
Later I wanted to climb a bit to get some more separation to some mountains. So I set the altitude bug to 10,000, punched in FLC mode again and set it to 100kts. AP pitched to maintain the 100kt speed and leveled off as expected at 10,000 ft.
After clearing the mountains I decided to descend back to 8,000. Set altitude bug to 8,000, selected VS mode, -500 fpm, and decreased throttle a little bit to maintain a constant speed. The AP descended at the requested rate and leveled off at 8,000 ft, at which point I increased throttle back to the original cruise setting.
I planned this flight in LittleNavMap using Victor airways, AP has had no problem following all heading changes at intersections. (Via GPS, not using actual VORs)
I will say I had very poor AP performance in all aircraft back in August immediately after launch. This seemed to be related to having the manual trim mapped to an axis interfering with the AP. I mapped them to 2 buttons instead and the problem went away for me at that point.
It seems like not everyone is having the same experience with the sim, so I’ll admit this is just my experience.
I do think that Asobo should provide a manual explaining the operation of the default avionics and any way that it differs from the actual real-life Garmins - especially since the Garmin implementations are missing a lot of features, which makes it unclear if a given feature is implemented, not implemented, implemented differently from the real thing, or broken and needs a bug report. If anyone else shares this feeling, please consider upvoting this wishlist item that I created asking for official documentation - Add a 'Learning Center' or other official documentation