Mike7
WKR
P.S. -- Ya, agree with the better/lighter bag with a liner like Sea-to-Summit (20 degree bag is fine for me).
Being a big guy I seriously suggest you make sure you are comfortable with the shoulder girth in some of these bags you are suggesting. I have a Marmot Wizard that has a 64" shoulder girth and it is too narrow to think about spending 10 nights in. The Cat's Meow you've got is 64"...try it out for an extended period before you dump 5-6 hundred dollars.