I had always used a tent until about 3 years ago. I switched to a gore-tex bivy, then a tarp with a BPL bivy and have looked back only once.
Ray Jardine’s book really made me think about things. The issue came to a head during a storm in Yosemite, while I had a tent instead of my tarp. Usually, Yosemite is pretty dry this time of year, but I was caught in a rainstorm near Glacier Point earlier in the season. I used my tent in March and was caught in a storm at Glacier Point. I was in about 8 feet of snow, but was wishing for my tarp when the condensation started in the tent and I had to cook in the rain. My equipment became quite wet while putting up the tent.
The sense of feeling exposed in a tarp was something I worried about, but it really never came to me as an issue.
What did hit me was bugs and dirt, both of which are tougher to keep away from with the tarp. I use the netting over my face in the BPL bivy and that pretty much solved the problem. I have a light groundsheet that helps with the rest, although I still throw dirt on myself at times.
The extra headroom with the tarp compared to my one-man tent is a good thing. The tent feels cramped and weighs 2 lbs more.
Except in real winter/4-season conditions, my tents will stay home. I just ordered a Henry Shires tarp/tent, so I will be able to compare it to the tent and tarp and choose what seems best.
Thanks, steve