My experience is gliding is much more useful than powered/PPL as a first step.
Much more head out of the cockpit required where flying the aeroplane is only a (small) part of the task at hand.
As a QFI, if you had a student with gliding experience, you had struck gold. Good stick and rudder skills, could fly attitudes without an AI, head always out of the cockpit - and teaching PFLs was a doddle!