Thanks to all that commented--Some very good ideas, tips, and observations for me to work with!
When I bought my WBBB 1.1 I ordered the strap system. When I got it, I didn't like it, so I ordered some Slap Staps because I liked the adjustable loops. I'm not all that worried about the extra weight as I am not a gram weenie.
Fortunately I have not used the Slap Straps yet (in fact haven't even received them yet)--after reading the comments about them stretching, I will return them and get the Atlas straps!
My friend Alan (PHARROAH) just got slings for his Hennessey, and we're supposed to do a hang next weekend, so I will get to see them in use and make a final decision. I will probably use the straps that came on the bird for that trip--just so I can make a good comparison.
"YOU KIDS GET OUTSIDE AND AIR YOUR PANTS!"--MOM