I think I saw a post where Brandon did a triple layer for someone.
That would be me. It made a very stout feeling hammock, with very little stretch. It allows me to lie back and relax with out fear of dropping through the bottom. It's also a good bit easier to get out of since the bottom doesn't stretch. I am close to 400lbs. I picked up a speer 1.1 Single layer ( I got it really cheap) just to what would happen when I got in it. It held but it stretched a lot. It was a bit scary. I have an Eno double wide thats a Single bottom its not scary to lay but it does stretch a good bit with me in it, it makes it a bit hard to get out of. I think the double 1.7 would have been more than enough to hold me but for the investment I wanted to be sure. So far I am very pleased. I am hoping to try it out overnight next weekend.