Aaaah yes, the dreaded Sproule net.
We had them on the SAR flights in the 60s but only for body(long-dead!) recovery. They were introduced originally because the Dragonfly/Sycamore etc didn't have the lifting capacity to carry two winch crew - Winch Op and Winchman. The idea was reasonable but the reality was problematical. Unless the sea surface was near flat, the front bar of the net would start to 'walk' and it became almost impossible to get the net into the water and under the 'survivor'. Rumour had it that this lead to a 'nasty' during a demo down West!! Anyway we had them available but rarely used in anger. The Whirly 10 gave the extra 'welly' for using a winchman and the results were much more predictable and faster.
Our yank cousins continued to use their similar version even for astronaut recovery but, on a personal basis, the demise of the Sproule net was most welcome!!