I have seen no data for the reliability of ballistic recovery
systems in sailplanes (or, indeed, in ULM/Microlights) but the
German data for survivability of conventional parachute bail-
outs from gliders makes very sobering reading.
I'd be very surprised if ballistic recovery chutes didn't turn out
to have a better record than conventional parachutes.
A majority of ULM/Microlights here in France have ballistic
recovery systems; you don't here of malfunctions very often,
but again I have no data.
I know three glider pilots who have had mid-airs, all three
bailed out, only one is still alive.
Dave W