View attachment 8653 Tarp is good because it's versatile, light, cheap, and effective. As an earlier poster pointed out, you have better vision around you and it makes it harder to sneak up on you.
However...
I have a small tent in my BOB because of my circumstances here in South Florida.
It's very tropical, and mosquitoes, biting flies, bot flies, gnats, and so on make life miserable. These insects can even carry serious diseases like West Nile, LaCrosse Encephalitis, Zika, and Dengue to name a few.
I use a small tent so I can have the benefit (with the mesh panels) of insect protection, and a good night's sleep so that I can be more alert the next day.
A third alternative that hasn't been mentioned is the tropical covered hammock.
It has a rainproof cover, and side mesh ventilation panels to keep out the insects. Walmart has one for $29.00, and it's actually lighter than a tent or a tarp.