IMO swags have little to recommend them when compared to lightweight dome hiking tents.
I have my Mountain Designs 3 man tent up inside 5 minutes. As it is self supporting doesn't even need pegs, unless rain is likely.
Designed as a snow tent, packs down small and is really light.
I find that good self inflating sleeping mats ( Thermarest or equiv.) are more than adequate for a good nights sleep in my down sleeping bag.
AND no risk of stuffing my back manhandling a swag with foam mattress onto the roof rack and tying it down.
Perhaps if I was older / carrying more weight I would want more.