If their Polyester they should not stretch but if you have the money I would try the whoopie sling because it is lighter and if you use a bishops bag it reduces the ammount of bags you have to carry to 2 instead of three (tarp, hammock, straps). I am planing to go to whoopie very soon I will be upgrading my hammock over the winter by about 200 bucks.
Bacon and Camping makes me happy.
"When life gives you lemons throw them back"
I camp in bear country and I am a bear Burrito.