I was going to build some prototypes. Then I read about the need for further crossover work with conical use and that project went on the back burner. I'm pretty happy with my tratrix salad bowls so I haven't had much motivation to revisit them.
Conical horns whos using them and your opinion
On performance of such. I have been experimenting for 2 years with conical. I have also used most all flares and horn types about. I do feel there is something special about the conical performance. They are a pain to build and integrate due to size the ranges are narrow but they do disappear when in use image better than other flares wave guides I've used. Not sure I'm sold on it yet but seems to me a good route to explore. Wonder what other users of conical horns could add.