my experience
i have been into sailplanes for many years (i enjoy catching thermals).
at the beginning, they were free flight (there was no radio control at the time). from 18" hand launch, to about 60" (1.5m) towline.
then, when radio control became practical and affordable, i got into that.
planes from 1.5 m to 2.5mt. then electric motor to assist climb.
the 1.5 seemed easier to handle and store, so worked with them for some time.
then went into 2 mt. 1st with 2 pieces wing. then 1 piece.
eventually i settled to 2 mt. and 1 piece wing-no ailerons, flaps, spoilers-nothing. just clean simple 3 channels. learned that don't need ailerons for thermaling.
learned that larger required 2 pieces wing, and made things more complicated than i needed-and couldn't see any improvement in flight, and also thermaling required larger size thermals.
am beginning to understand why the 2 mt is the most popular.
but that of course depends on each 1.