Bronco doesn't work that well for me. It is great at first but if I go for a ride and they get sweaty, it's like I never sprayed them. Plus we have got everything from gnats, noseeums, mosquitos, face flies, regular flies, horse flies, deer flies, and some other type that is like over an inch long. I am glad you started this post because I also need to find something that will work well and for a long time.
Fly management is not the issue with me as I ride lots of trails through trees, along creeks, and amongst cattle so i pick up flies everywhere and bring them home with me. LOL.