Trimming is completely relative to your aircraft speed.
Fly 'Wet', Hands on, use AP, pitch, AH, thats what it's there for.
Trim when you NEED to. Uneven weight distribution under wing surfaces or damaged airframe.
IMHO, it's a matter of personal choice and in no way mandatory. i fly in formation 'Hands on' I fly lead on AP. Horses for courses, whatever takes ya fancy.
'T'