I prefer the standard "GI" 2 point sling.
Ditto. I have two & both have two-point GI cloth slings. I have no interest in appearing "tacti-cool," I'm no longer crashing through doors wearing body armor and ninja stuff and I'm not planning a trip to Afghanistan any time soon, so for my purposes, the GI sling works perfectly.
For covert carry however, I discovered from one of the gun forums I belong to, what is called a "gig bag." What that is, is a soft sided electric guitar case. Someone sees a guy walking down the street carrying a gun case, there may be a call to 9-1-1 happening very soon. Dumb, I know, but it happens. See an old guy walking down the street with a guitar case on his back, and most folks don't give you a second look. I got the kind that has back pack straps & outside pockets perfect for spare magazines. I built up the inside with foam rubber to keep it's shape. Set me back about $15.00. Google "gig bag" and check them out. Lots of colors and options. I even fooled my gun savvy son, who thought the old man had gone over the edge and turned hippie.