There's a sample provided by esri named GpsSample (I can't find a way to upload it here)
Anyway, the sample includes multiple selections for mapview's locationDisplay autoPanMode property
I'm trying to implement it in a similar way, my code is the same, difference is I'm creating the UI controls dynamically (mapview included) without relying on static XIBs
Debugging the code, the autoPanMode property for the map changes correctly but the mapview still wouldn't be automatically rotated like in the provided sample
Finally, I set mapview's allowRotatingByPinching to YES, the map and attached compass image are rotating correctly via pinching. But still wouldn't automatically rotate itself.