I think the question is defined by "need" or "want"- do i need an AP ? no, I can fly IMC with my own hands and head or i should not up there to start with - do i want one? yes, it reduces the potential for mistakes that could go from embarrassing to other worldly- the issue is also one of a matter of other problems and as an aviator i know other problems all too well- they occur at the worst possible moment often appearing in groups for some reason- without an AP a small problem like forgetting to switch tanks can lead to a momentary distraction followed then by an errant engine noise leading me down a path from which i may not return if i am hand flying - i see the AP as something similar to another set of hands and another head- i only need to manage the AP correctly and then it can manage many other things whilst i switch tanks