It seems to me like manufacturers love to load their AFCS with so many extras, maybe to try and out-spec the competition that they forget that a good AFCS does all the basics well through a simple, uncomplicated interface.
A pilot on a high pressure IMC go around shouldn't need to remember umpteen modes and sub modes, engagement parameters etc - if it says GA on the button, it should do exactly that and it should work seamlessly with the FMS.
Unfortunately I get the impression that engineers design AFCS/FMS forgetting that pilots need to be able to use it easily.
Not so much the new AFCS. The Helionix GA is exactly what you want - maintains track, initiates a climb to the preset altitude, holds airspeed, manages NR in the event of OEI and initiates the missed approach in the FMS. Scarily dull. The older AP2000 was awful...it initiated a climb but just held the trimmed roll attitude even if that happened to be 30. Nasty.