There's no doubt that head-rigged assists provide for an ideal hook placement with lower risk of pulling hooks. However, on the otherhand - the hook-up ratio is very poor.
Hook retention fantastic, opportunity conversion poor.
My fishing and the practices I teach is that all fishing should be considered and applied on the actual circumstances, variables and environment presented. This means I fish a variety of hook types and configurations.
A majority of lures are designed to be fished with trebles. The hook exposure is superior to singles, however, the damage can be significant. It's encouraging to see a number of boutique lure craftsmen addressing the industry with poppers and stickbaits suited to running single hook configurations. It's always going to be a trade off with single hooks providing poor hook exposure and unfavorable characteristics in respect to working with a lure to swim and sometimes enhance action. I still observe the occasional foul hooked GT via singles which is an absolute nightmare to fish - the rear single placement is perfect for hook-up in gill-plate, gulls and flank.
At the end of the day, we need to accept some things for what they are. Trebles, in my opinion, will always have a place in GT fishing. Singles, are becoming increasingly popular and I will use them when the conditions dictate (such as high-level, frenzied feeding where GTs coming back for multiple attacks is a sure thing).
GT fishing is the ultimate hunt. We need to find the right compromise between catching our quarry whilst promoting the safes and most efficient means to both fish and angler.
Luke