That's interesting using heads. I was going to write a FP on the virtues of the DT line today, but instead picked the casting planes topic. It's interesting that with many fly lines being short heavy WF lines with a thin running line that many manufacturers have moved significantly away from DTs are are much more aligned to Shooting Heads. Of course Shooting Heads have a place, particularly when covering large areas of water, but I find it curious that people arm themselves with such tackle even when there are many types of fishing where the fish are targeted within only a few rod lengths. One of the biggest errors in fly fishing for trout, whether that be on rivers or stillwaters, is simply casting too far.
Then again it does come back to the fishing that we are teaching. If I was living in Denmark for example, fishing the coast for Imaginary Sea Trout, then I'm quite sure that I would very quickly teach with shooting heads. That is in fact the only place I have fished shooting heads by the way, apart from a brief go with them fishing off the dam when I was about 15.
I teach that there are four disciplines in flycasting; Accuracy, Distance, Speys and Presentation Casts. For me Shooting Heads are about Distance (and distance with Speys). I haven't fished much in the UK in recent years. Are Shooting Heads being commonly used in the lakes nowadays? They were exceptionally rare to see when I was working on Ardlegh Res.
I teach with a lot of different outfits here, but my favourite is the HT6 and Lumiline DT6. I get really solid results with that which can then be applied to whatever else we are using, which is usually a ten weight.