The way the bags are shaped on the backside, it seems like mounting them the way Robmay has them would be best for avoiding rubbing. Guess I'll give that a try and see what happens. These things came with zero preload in 'em, so looks like I'll be following the measuring process outlined in the manual. 
Mounted like that, the resevoir sits close to the edge of the shock recess, hitting right on the corner, running up and down for an inch or two.
I just check both of my bags and I have rubbing on the right bag only. It starts about 4 inches from the top edge of the bag and the rub is about 2 inches long. It's through all layers of the paint and into the plastic of the bag some.
If you run with a stabilizer, I would assume there would be less chance of rubbing as there would be less lateral movement of the rear wheel.
Hmmmmm. maybe it's time to get one of the Bagger Braces.

