Love my thermocell. Benefits are its compact, repels mosquitos like magic. They dont even buzz around you. These units are very easy to use. I turn mine on when I leave the truck and keep it on for at least the first 2 hours in stand when the mosquitos are usually at their worse. Drawback is it can get expensive if you use it alot.
Each kit has 3 matts and one butane cartridge for around 6 or 7 dollars per kit.
Each kit lasts about 12 hours,(4 hr. per chemical matt). This unit is also a little less effective in breezy conditions, however, breezy conditions usually keep the mosquitos at bay anyway. My normal use is 2hr in the morning and 2 hr in the evening at the times when the mosquitos are at their worse.