I have slept in 206s, Astars, and UH1s, and that is pretty much in increasing order of comfort, except for a couple of nights in a UH1 with no seats in the back. The floor gets really cold and hard. I've also spent many hours sleeping on the helideck of offshore platforms, using the seatbacks from 206L models to lie on, but the best way was tying a hammock to the handrails, or in a pinch, to the tail stinger and the tiedown shackle. I used to carry a nylon rollup hammock with me for those long days shut down on unmanned platforms with no facilities at all. I've also slept inside life jacket boxes - some are about the size of a casket, and filled with kapok life vests. They make fine sleeping facilities when it's raining and blowing 40 knots in the winter, far, far better than the back seat of a 206.