dan,
if you are casting around snags it wont matter what net you use, mono will tear quicker then nylon. stay away from rocks & snags!
i have a drawstring & my mate has a top pocket, side by side in the boat i got twice as many prawns then he did,the drawstring cause very little damage to the bait. no sinkers smashing into them as the leadline gets gathered up to the top leaving the bait to rest on the mono at the bottom. have heard people say that they get alot of tangles with a drawstring, this is so but it only takes a second to go through the lead line getting them out, i do this about every third cast. in saying this there is nothing wrong with a top pocket either.
ron.