I have 1000hrs in '20 with zero spins or surprising stalls. Load any glider from same vintage to aft c/g and it will spin, especially if you do not know how to deal with wing drop (excellent example posted on this forum just recently). Any flapped glider will stall and spin more abruptly with positive flaps. ASW20 being "killer" is OWT of all times. Puchacz is a killer, yes. '20, no.