Eh.....sorta disagree, sorta depends on your physical stuff and the glider.
I'm 5' 10", slim build (usually have to add nose ballast in some glass I fly....sorry owner.....;-)).
Some pilots can use a "back pack", some need a "chair pack", sorta depends on the glider and the pilot.
Thankfully for me, I fit almost anything with my normal chute, but not the same for others (Chip is about my build, but a bit taller.....).
Yes, I have done 7hr flights in glass, can't imagine more than 3 in a 1-26..,.... skinny butt, more upright......go get'm Ron S.

YMMV.......