We still had the Sproule net available to the RAF SAR Whirlwinds in the 70's but they were never used operationally to recover live people as there was too much likelihood of damaging the survivor. The double lift was the standard method. The idea of the net was to avoid having to hover with the marginally powered piston engined types. The turbine jobs were somewhat better off for power.
However the net was used to recover drowned bodies to the relief of the winchman.