A bough bed is great but I always struggle with the LNT ethos when it comes to that. A good deal of the time I might be in a national or provincial park where cutting boughs would be a no no. Outside of parks and in Canadian boreal forest it's probably OK but I still feel a bit of a guilty pain when I start stripping trees for boughs even if it just the lower 6'. Hmm, maybe I just need to get over it?

And I am often in simple mixed forest parkland of birch and poplar or I am in the basic prairie - for me there is only way to go.
I.e. the tent or a tarp with a netting which combined is basically the same weight as the tent and 2x as long to set up.

I basically discount the contained heat advantage of the shelter, as a tent may only be a degree or two warmer than the surrounding air. For some reason people have this silly idea that a tent is there so that you can put a heater in it and keep you warm! Silly concept I'd say. If your bag/pad doesn't keep you warm, you could use extra clothing. And if that isn't sufficient then you brought the wrong bag!
The biggest thing about a shelter for me is to block the wind which will make you feeler much cooler than the surrounding air. A couple years ago, I was out with a group of lesser experienced people. One guy who hit the sack early had buttoned up the tent tight so that it wouldn't ventilate and then complained about his bag getting moist. The next night we opened all the vents and were dry and warm. He did not understand that a tent needs to breathe and should not be shuttered tight for it to work properly.

"Comfort is relative." Couldn't agree more - for me I like my 1.5" inflatable pad and -12*C bag. Although I've used the 0*C bag in temps as low as -8*C by wearing my extra clothes. I also build a pillow / neck rest from clothes and ditty bags. Some people can get by with a simple 3/8" x 3/4 length foamy on hard ground and use a quilt!

It is also quite normal to wake up a few times in the middle of the night to roll over or adjust your sleeping position. To sleep through an entire night without doing so is a pipe dream for me - I simply have to move about.

Some people like the visual "privacy" of a tent or think that it will eliminate the sound of people talking from the next tent. I'm not sure where they get that idea from.