Hi,
We tent camp and just flake out under the stars all the time with our dog.
When in a tent, she sleeps much better (the den thing I guess). When outside, she usually has one eye open all night .... which is sort of nice too because then she is tired the next day (-:
When she was younger, we used to keep her on a leash at night, but now we are comfortable that she doesn't roam. When bears come to visit at night (frequently in some of the places we visit) it is nice to have the early warning system, often just a low growl .... and the bears "usually" nicely just go away before we have to bother getting up to defend the food. Keep in mind though she is very well trained and has been camping with us since she was about 4 months old (then she slept in a crate....to save our gear from being scattered all over creation).
Regarding cots. There are pro's and con's.
- They are higher and easier to get up from. You will also sleep cooler on them (great for hot, think bottom of the Grand Canyon hot, sand in the summer). They also keep critters off (scorpions, spiders, toads, Banana slugs in the PNW, etc.)
On the flip side, they are cooler sleeping (i.e.; not good in the PNW most of the time), and are heavy and take up a lot of room to store. As for being in a tent, they can be tough on the tent floor and I would recommend a floorless tent, putting a heavy canvas under the feet, or just sleeping under the stars. Because you are higher up, a little tent just won't cut it. You will need a full size (wall) tent...which takes up more room again.
Leaving for a trip (mixed travel trailer and backpacking) tomorrow (yes, our dog is going), but if you have other questions that you would like to ask me, feel free to send me a PM me as I am unlikely to recheck this post before I leave.