Comfort is number 1 as others have mentioned, it just can't be beat. There are some who cannot get comfortable in a hammock but that is rare.

As far as weight, in general a hammock setup will be lighter than a tent setup, but heavier than a tarp setup. For me, the comfort level of the hammock easily makes up the slight weight penalty.

Other benefits include:
-setup over rocky or rooted ground which is inhospitable to ground dwellers
-staying dry is easier as one doesn't need to worry about ground water

Some might ask about difficulty in finding places to hang, I have never been at a loss for trees in the woods and they do not have to be a perfect distance apart. Sometimes I may have to camp a little farther away from the ground people, but that can be a good thing. Or one could look at it as the ground people had limited choices to camp.

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