the bungee type is supposed to be more comfortable... can't even find any written reviews online. Only thing I found is this one video review:
edit: btw, the only viable advantage I see to a bungee type sling is that it would tighten up when the sling wasn't around you so there wouldn't be excess sling hanging down that could get in the way should you choose to shoot without wearing the sling.
Royal Arms makes the finest of the bungee type slings. For their stated purpose keeping the scatterguns close to your body and out of the way, they are superb. Most times they are used by TAC officers to keep door breaching guns out of the way when not in use. Here is the web site for the sling. http://www.royalarms.com/
Good Luck & Stay Safe
First, with the most, WINS!
Regards, Scattergun Bob