Ive been using the thermacell in the Q for 4 years now and it works great. The mosquitos keep about a 15 foot radius around you but there are still a few black flies. The down side is that it doesn't work at all when moving so in the portages you still need some other kind of protection and the ankle biters still get you in the canoe. But in camp it is invaluable and i'll never leave without it!